Method for transmitting and receiving positioning reference signal and apparatus therefor

ABSTRACT

Disclosed is a method for a terminal for receiving a positioning reference signal (PRS) in a wireless communication system. Particularly, the method includes: receiving first information related to a PRS resource group including a plurality of PRS resources, and second information related to a repetition count for the PRS resource group; and receiving a PRS on the plurality of PRS resources based on the first information and second information, wherein the PRS resource group may be allocated repeatedly as many times as the repetition count within a certain period.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/KR2019/014789, filed on Nov. 4, 2019, which claims the benefit ofKorean Application No. 10-2018-0133998, filed on Nov. 2, 2018. Thedisclosures of the prior applications are incorporated by reference intheir entirety.

TECHNICAL FIELD

The present disclosure relates to a method and apparatus fortransmitting and receiving a positioning reference signal (PRS), andmore particularly, to a method and apparatus for transmitting andreceiving a PRS by repeatedly allocating PRS resources to increase theaccuracy of positioning.

BACKGROUND

As more and more communication devices demand larger communicationtraffic along with the current trends, a future-generation 5thgeneration (5G) system is required to provide an enhanced wirelessbroadband communication, compared to the legacy LTE system. In thefuture-generation 5G system, communication scenarios are divided intoenhanced mobile broadband (eMBB), ultra-reliability and low-latencycommunication (URLLC), massive machine-type communication (mMTC), and soon.

Herein, eMBB is a future-generation mobile communication scenariocharacterized by high spectral efficiency, high user experienced datarate, and high peak data rate, URLLC is a future-generation mobilecommunication scenario characterized by ultra high reliability, ultralow latency, and ultra high availability (e.g., vehicle to everything(V2X), emergency service, and remote control), and mMTC is afuture-generation mobile communication scenario characterized by lowcost, low energy, short packet, and massive connectivity (e.g., Internetof things (IoT)).

SUMMARY

An aspect of the present disclosure is to provide a method and apparatusfor transmitting and receiving a positioning reference signal (PRS).

It will be appreciated by persons skilled in the art that the objectsthat could be achieved with the present disclosure are not limited towhat has been particularly described hereinabove and the above and otherobjects that the present disclosure could achieve will be more clearlyunderstood from the following detailed description.

In an aspect of the present disclosure, a method of receiving apositioning reference signal (PRS) by a user equipment (UE) in awireless communication system includes receiving first informationrelated to a PRS resource group including a plurality of PRS resourcesand second information related to a repetition number for the PRSresource group, and receiving the PRS in the plurality of PRS resourcesbased on the first information and the second information. The PRSresource group may be allocated repeatedly as many times as therepetition number within a predetermined period.

The predetermined period may be a PRS occasion spanning a lengthobtained by multiplying a time period for the PRS resource group by therepetition number.

Further, the predetermined period may be equal to or shorter than atransmission periodicity of the PRS.

Further, a maximum number of PRS resources configurable for the UE maybe determined based on a capability of the UE.

Further, the method may further include receiving information related aPRS transmission timing offset between a plurality of cells, and thereception of the PRS may include receiving the PRS based on the PRStransmission timing offset.

Further, the method may further include obtaining information related toan angle of a transmission beam for the PRS.

Further, the UE is communicable with at least one of a UE other than theUE, a network, a base station, or an autonomous driving vehicle.

In another aspect of the present disclosure, an apparatus for receivinga PRS in a wireless communication system includes at least oneprocessor, and at least one memory operatively connected to the at leastone processor and soring instructions which when executed, cause the atleast one processor to perform a specific operation. The specificoperation includes receiving first information related to a PRS resourcegroup including a plurality of PRS resources and second informationrelated to a repetition number for the PRS resource group, and receivingthe PRS in the plurality of PRS resources based on the first informationand the second information. The PRS resource group may be allocatedrepeatedly as many times as the repetition number within a predeterminedperiod.

The predetermined period may be a PRS occasion spanning a lengthobtained by multiplying a time period for the PRS resource group by therepetition number.

Further, the predetermined period may be equal to or shorter than atransmission periodicity of the PRS.

Further, a maximum number of PRS resources configurable for the UE maybe determined based on a capability of the UE.

Further, the specific operation may further include receivinginformation related a PRS transmission timing offset between a pluralityof cells. The reception of the PRS may include receiving the PRS basedon the PRS transmission timing offset.

Further, the specific operation may further include obtaininginformation related to an angle of a transmission beam for the PRS.

Further, the apparatus is communicable with at least one of a UE, anetwork, a base station, or an autonomous driving vehicle.

In another aspect of the present disclosure, a UE for receiving a PRS ina wireless communication system includes at least one transceiver, atleast one processor, and at least one memory operatively connected tothe at least one processor and storing instructions which when executed,cause the at least one processor to perform a specific operation. Thespecific operation includes receiving first information related to a PRSresource group including a plurality of PRS resources and secondinformation related to a repetition number for the PRS resource groupthrough the at least one transceiver, and receiving the PRS in theplurality of PRS resources based on the first information and the secondinformation through the at least one transceiver. The PRS resource groupmay be allocated repeatedly as many times as the repetition numberwithin a predetermined period.

According to the present disclosure, the accuracy of positioning may beincreased by repeatedly allocating positioning reference signal (PRS)resources.

It will be appreciated by persons skilled in the art that the effectsthat can be achieved with the present disclosure are not limited to whathas been particularly described hereinabove and other advantages of thepresent disclosure will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are diagrams illustrating the control-plane anduser-plane architecture of radio interface protocols between a userequipment (UE) and an evolved UMTS terrestrial radio access network(E-UTRAN) in conformance to a 3^(rd) generation partnership project(3GPP) radio access network standard.

FIG. 2 is a diagram illustrating physical channels and a general signaltransmission method using the physical channels in a 3GPP system.

FIGS. 3, 4 and 5 are diagrams illustrating structures of a radio frameand slots in a new radio access technology (NR) system.

FIGS. 6 and 7 are diagrams illustrating the structure of asynchronization signal block (SSB) and a method of transmitting an SSB.

FIG. 8 is a diagram illustrating a channel state information (CSI)reporting process.

FIGS. 9A and 9B illustrate exemplary mapping of a positioning referencesignal (PRS) in a long term evolution (LTE) system.

FIGS. 10 and 11 are diagrams illustrating the architecture of a systemfor positioning a UE and a procedure of positioning a UE.

FIG. 12 is a diagram illustrating an exemplary protocol layer stack forsupporting transmission of an LTE positioning protocol (LPP) message.

FIG. 13 is a diagram illustrating an exemplary protocol layer stack forsupporting transmission of an NR positioning protocol A (NRPPa) protocoldata unit (PDU).

FIG. 14 is a diagram illustrating an embodiment of an observed timedifference of arrival (OTDOA) positioning method.

FIGS. 15 to 18 are diagrams illustrating implementation examples ofoperations of a user equipment (UE), a base station (BS), and a locationserver according to an embodiment of the present disclosure.

FIGS. 19A and 19B are diagrams illustrating an embodiment of PRSallocation according to the present disclosure.

FIGS. 20A and 20B are diagrams illustrating an embodiment of reportingposition-related information according to the present disclosure.

FIGS. 21 to 26B are diagrams illustrating embodiments of allocating PRSresources in a slot according to the present disclosure.

FIGS. 27A and 27B are diagrams illustrating implementation examples of aPRS transmission (Tx) beam configuration according to the presentdisclosure.

FIG. 28 is a diagram illustrating an exemplary wireless communicationsystem to which embodiments of the present disclosure are applied.

FIGS. 29 to 32 are diagrams illustrating exemplary various wirelessdevices to which embodiments of the present disclosure are applied.

FIG. 33 is a diagram illustrating an exemplary location server to whichembodiments of the present disclosure are applied.

FIG. 34 is a diagram illustrating an exemplary signal processing circuitto which embodiments of the present disclosure are applied.

DETAILED DESCRIPTION

The configuration, operation, and other features of the presentdisclosure will readily be understood with embodiments of the presentdisclosure described with reference to the attached drawings.Embodiments of the present disclosure as set forth herein are examplesin which the technical features of the present disclosure are applied toa 3rd generation partnership project (3GPP) system.

While embodiments of the present disclosure are described in the contextof long term evolution (LTE) and LTE-advanced (LTE-A) systems, they arepurely exemplary. Therefore, the embodiments of the present disclosureare applicable to any other communication system as long as the abovedefinitions are valid for the communication system.

The term, base station (BS) may be used to cover the meanings of termsincluding remote radio head (RRH), evolved Node B (eNB or eNode B),transmission point (TP), reception point (RP), relay, and so on.

The 3GPP communication standards define downlink (DL) physical channelscorresponding to resource elements (REs) carrying information originatedfrom a higher layer, and DL physical signals which are used in thephysical layer and correspond to REs which do not carry informationoriginated from a higher layer. For example, physical downlink sharedchannel (PDSCH), physical broadcast channel (PBCH), physical multicastchannel (PMCH), physical control format indicator channel (PCFICH),physical downlink control channel (PDCCH), and physical hybrid ARQindicator channel (PHICH) are defined as DL physical channels, andreference signals (RSs) and synchronization signals (SSs) are defined asDL physical signals. An RS, also called a pilot signal, is a signal witha predefined special waveform known to both a gNode B (gNB) and a userequipment (UE). For example, cell specific RS, UE-specific RS (UE-RS),positioning RS (PRS), and channel state information RS (CSI-RS) aredefined as DL RSs. The 3GPP LTE/LTE-A standards define uplink (UL)physical channels corresponding to REs carrying information originatedfrom a higher layer, and UL physical signals which are used in thephysical layer and correspond to REs which do not carry informationoriginated from a higher layer. For example, physical uplink sharedchannel (PUSCH), physical uplink control channel (PUCCH), and physicalrandom access channel (PRACH) are defined as UL physical channels, and ademodulation reference signal (DMRS) for a UL control/data signal, and asounding reference signal (SRS) used for UL channel measurement aredefined as UL physical signals.

In the present disclosure, the PDCCH/PCFICH/PHICH/PDSCH refers to a setof time-frequency resources or a set of REs, which carry downlinkcontrol information (DCI)/a control format indicator (CFI)/a DLacknowledgement/negative acknowledgement (ACK/NACK)/DL data. Further,the PUCCH/PUSCH/PRACH refers to a set of time-frequency resources or aset of REs, which carry UL control information (UCI)/UL data/a randomaccess signal. In the present disclosure, particularly a time-frequencyresource or an RE which is allocated to or belongs to thePDCCH/PCFICH/PHICH/PDSCH/PUCCH/PUSCH/PRACH is referred to as a PDCCHRE/PCFICH RE/PHICH RE/PDSCH RE/PUCCH RE/PUSCH RE/PRACH RE or a PDCCHresource/PCFICH resource/PHICH resource/PDSCH resource/PUCCHresource/PUSCH resource/PRACH resource. Hereinbelow, if it is said thata UE transmits a PUCCH/PUSCH/PRACH, this means that UCI/UL data/a randomaccess signal is transmitted on or through the PUCCH/PUSCH/PRACH.Further, if it is said that a gNB transmits a PDCCH/PCFICH/PHICH/PDSCH,this means that DCI/control information is transmitted on or through thePDCCH/PCFICH/PHICH/PDSCH.

Hereinbelow, an orthogonal frequency division multiplexing (OFDM)symbol/carrier/subcarrier/RE to which a CRS/DMRS/CSI-RS/SRS/UE-RS isallocated to or for which the CRS/DMRS/CSI-RS/SRS/UE-RS is configured isreferred to as a CRS/DMRS/CSI-RS/SRS/UE-RS symbol/carrier/subcarrier/RE.For example, an OFDM symbol to which a tracking RS (TRS) is allocated orfor which the TRS is configured is referred to as a TRS symbol, asubcarrier to which a TRS is allocated or for which the TRS isconfigured is referred to as a TRS subcarrier, and an RE to which a TRSis allocated or for which the TRS is configured is referred to as a TRSRE. Further, a subframe configured to transmit a TRS is referred to as aTRS subframe. Further, a subframe carrying a broadcast signal isreferred to as a broadcast subframe or a PBCH subframe, and a subframecarrying a synchronization signal (SS) (e.g., a primary synchronizationsignal (PSS) and/or a secondary synchronization signal (SSS)) isreferred to as an SS subframe or a PSS/SSS subframe. An OFDMsymbol/subcarrier/RE to which a PSS/SSS is allocated or for which thePSS/SSS is configured is referred to as a PSS/SSS symbol/subcarrier/RE.

In the present disclosure, a CRS port, a UE-RS port, a CSI-RS port, anda TRS port refer to an antenna port configured to transmit a CRS, anantenna port configured to transmit a UE-RS, an antenna port configuredto transmit a CSI-RS, and an antenna port configured to transmit a TRS,respectively. Antenna port configured to transmit CRSs may bedistinguished from each other by the positions of REs occupied by theCRSs according to CRS ports, antenna ports configured to transmit UE-RSsmay be distinguished from each other by the positions of REs occupied bythe UE-RSs according to UE-RS ports, and antenna ports configured totransmit CSI-RSs may be distinguished from each other by the positionsof REs occupied by the CSI-RSs according to CSI-RS ports. Therefore, theterm CRS/UE-RS/CSI-RS/TRS port is also used to refer to a pattern of REsoccupied by a CRS/UE-RS/CSI-RS/TRS in a predetermined resource area.

Now, 5G communication including an NR system will be described.

Three main requirement categories for 5G include (1) a category ofenhanced mobile broadband (eMBB), (2) a category of massive machine typecommunication (mMTC), and (3) a category of ultra-reliable and lowlatency communications (URLLC).

Partial use cases may require a plurality of categories for optimizationand other use cases may focus only upon one key performance indicator(KPI). 5G supports such various use cases using a flexible and reliablemethod.

eMBB far surpasses basic mobile Internet access and covers abundantbidirectional tasks and media and entertainment applications in cloudand augmented reality. Data is one of 5G core motive forces and, in a 5Gera, a dedicated voice service may not be provided for the first time.In 5G, it is expected that voice will be simply processed as anapplication program using data connection provided by a communicationsystem. Main causes for increased traffic volume are due to an increasein the size of content and an increase in the number of applicationsrequiring high data transmission rate. A streaming service (of audio andvideo), conversational video, and mobile Internet access will be morewidely used as more devices are connected to the Internet. These manyapplication programs require connectivity of an always turned-on statein order to push real-time information and alarm for users. Cloudstorage and applications are rapidly increasing in a mobilecommunication platform and may be applied to both tasks andentertainment. The cloud storage is a special use case which acceleratesgrowth of uplink data transmission rate. 5G is also used for a remotetask of cloud. When a tactile interface is used, 5G demands much lowerend-to-end latency to maintain user good experience. Entertainment, forexample, cloud gaming and video streaming, is another core element whichincreases demand for mobile broadband capability. Entertainment isessential for a smartphone and a tablet in any place including highmobility environments such as a train, a vehicle, and an airplane. Otheruse cases are augmented reality for entertainment and informationsearch. In this case, the augmented reality requires very low latencyand instantaneous data volume.

In addition, one of the most expected 5G use cases relates a functioncapable of smoothly connecting embedded sensors in all fields, i.e.,mMTC. It is expected that the number of potential IoT devices will reach204 hundred million up to the year of 2020. An industrial IoT is one ofcategories of performing a main role enabling a smart city, assettracking, smart utility, agriculture, and security infrastructurethrough 5G.

URLLC includes a new service that will change industry through remotecontrol of main infrastructure and an ultra-reliable/availablelow-latency link such as a self-driving vehicle. A level of reliabilityand latency is essential for smart grid control, industrial automation,robotics, and drone control and adjustment.

Next, a plurality of use cases in the 5G communication system includingthe NR system will be described in more detail.

5G is a means of providing streaming evaluated as a few hundred megabitsper second to gigabits per second and may complement fiber-to-the-home(FTTH) and cable-based broadband (or DOCSIS). Such fast speed is neededto deliver TV in resolution of 4K or more (6K, 8K, and more), as well asvirtual reality and augmented reality. Virtual reality (VR) andaugmented reality (AR) applications include almost immersive sportsgames. A specific application program may require a special networkconfiguration. For example, for VR games, gaming companies need toincorporate a core server into an edge network server of a networkoperator in order to minimize latency.

Automotive is expected to be a new important motivated force in 5Gtogether with many use cases for mobile communication for vehicles. Forexample, entertainment for passengers requires high simultaneouscapacity and mobile broadband with high mobility. This is because futureusers continue to expect connection of high quality regardless of theirlocations and speeds. Another use case of an automotive field is an ARdashboard. The AR dashboard causes a driver to identify an object in thedark in addition to an object seen from a front window and displays adistance from the object and a movement of the object by overlappinginformation talking to the driver. In the future, a wireless moduleenables communication between vehicles, information exchange between avehicle and supporting infrastructure, and information exchange betweena vehicle and other connected devices (e.g., devices accompanied by apedestrian). A safety system guides alternative courses of a behavior sothat a driver may drive more safely drive, thereby lowering the dangerof an accident. The next stage will be a remotely controlled orself-driven vehicle. This requires very high reliability and very fastcommunication between different self-driven vehicles and between avehicle and infrastructure. In the future, a self-driven vehicle willperform all driving activities and a driver will focus only uponabnormal traffic that the vehicle cannot identify. Technicalrequirements of a self-driven vehicle demand ultra-low latency andultra-high reliability so that traffic safety is increased to a levelthat cannot be achieved by human being.

A smart city and a smart home mentioned as a smart society will beembedded in a high-density wireless sensor network. A distributednetwork of an intelligent sensor will identify conditions for costs andenergy-efficient maintenance of a city or a home. Similar configurationsmay be performed for respective households. All of temperature sensors,window and heating controllers, burglar alarms, and home appliances arewirelessly connected. Many of these sensors are typically low in datatransmission rate, power, and cost. However, real-time HD video may bedemanded by a specific type of device to perform monitoring.

Consumption and distribution of energy including heat or gas isdistributed at a higher level so that automated control of thedistribution sensor network is demanded. The smart grid collectsinformation and connects the sensors to each other using digitalinformation and communication technology so as to act according to thecollected information. Since this information may include behaviors of asupply company and a consumer, the smart grid may improve distributionof fuels such as electricity by a method having efficiency, reliability,economic feasibility, production sustainability, and automation. Thesmart grid may also be regarded as another sensor network having lowlatency.

A health part contains many application programs capable of enjoyingbenefit of mobile communication. A communication system may supportremote treatment that provides clinical treatment in a faraway place.Remote treatment may aid in reducing a barrier against distance andimprove access to medical services that cannot be continuously availablein a faraway rural area. Remote treatment is also used to performimportant treatment and save lives in an emergency situation. Thewireless sensor network based on mobile communication may provide remotemonitoring and sensors for parameters such as heart rate and bloodpressure.

Wireless and mobile communication gradually becomes important in thefield of an industrial application. Wiring is high in installation andmaintenance cost. Therefore, a possibility of replacing a cable withreconstructible wireless links is an attractive opportunity in manyindustrial fields. However, in order to achieve this replacement, it isnecessary for wireless connection to be established with latency,reliability, and capacity similar to those of the cable and managementof wireless connection needs to be simplified. Low latency and a verylow error probability are new requirements when connection to 5G isneeded.

Logistics and freight tracking are important use cases for mobilecommunication that enables inventory and package tracking anywhere usinga location-based information system. The use cases of logistics andfreight typically demand low data rate but require location informationwith a wide range and reliability.

FIGS. 1A and 1B are diagrams illustrating the control-plane anduser-plane architecture of radio interface protocols between a userequipment (UE) and an evolved UMTS terrestrial radio access network(E-UTRAN) in conformance to a 3^(rd) generation partnership project(3GPP) radio access network standard. The control plane is a path inwhich the UE and the E-UTRAN transmit control messages to manage calls,and the user plane is a path in which data generated from an applicationlayer, for example, voice data or Internet packet data is transmitted.

A physical (PHY) layer at layer 1 (L1) provides information transferservice to its higher layer, a medium access control (MAC) layer. ThePHY layer is connected to the MAC layer via transport channels. Thetransport channels deliver data between the MAC layer and the PHY layer.Data is transmitted on physical channels between the PHY layers of atransmitter and a receiver. The physical channels use time and frequencyas radio resources. Specifically, the physical channels are modulated inorthogonal frequency division multiple access (OFDMA) for downlink (DL)and in single carrier frequency division multiple access (SC-FDMA) foruplink (UL).

The MAC layer at layer 2 (L2) provides service to its higher layer, aradio link control (RLC) layer via logical channels. The RLC layer at L2supports reliable data transmission. RLC functionality may beimplemented in a function block of the MAC layer. A packet dataconvergence protocol (PDCP) layer at L2 performs header compression toreduce the amount of unnecessary control information and thusefficiently transmit Internet protocol (IP) packets such as IP version 4(IPv4) or IP version 6 (IPv6) packets via an air interface having anarrow bandwidth.

A radio resource control (RRC) layer at the lowest part of layer 3 (orL3) is defined only on the control plane. The RRC layer controls logicalchannels, transport channels, and physical channels in relation toconfiguration, reconfiguration, and release of radio bearers. A radiobearer refers to a service provided at L2, for data transmission betweenthe UE and the E-UTRAN. For this purpose, the RRC layers of the UE andthe E-UTRAN exchange RRC messages with each other. If an RRC connectionis established between the UE and the E-UTRAN, the UE is in RRCConnected mode and otherwise, the UE is in RRC Idle mode. A Non-AccessStratum (NAS) layer above the RRC layer performs functions includingsession management and mobility management.

DL transport channels used to deliver data from the E-UTRAN to UEsinclude a broadcast channel (BCH) carrying system information, a pagingchannel (PCH) carrying a paging message, and a shared channel (SCH)carrying user traffic or a control message. DL multicast traffic orcontrol messages or DL broadcast traffic or control messages may betransmitted on a DL SCH or a separately defined DL multicast channel(MCH). UL transport channels used to deliver data from a UE to theE-UTRAN include a random access channel (RACH) carrying an initialcontrol message and a UL SCH carrying user traffic or a control message.Logical channels that are defined above transport channels and mapped tothe transport channels include a broadcast control channel (BCCH), apaging control channel (PCCH), a Common Control Channel (CCCH), amulticast control channel (MCCH), a multicast traffic channel (MTCH),etc.

FIG. 2 illustrates physical channels and a general method fortransmitting signals on the physical channels in the 3GPP system.

Referring to FIG. 2, when a UE is powered on or enters a new cell, theUE performs initial cell search (S201). The initial cell search involvesacquisition of synchronization to an eNB. Specifically, the UEsynchronizes its timing to the eNB and acquires a cell identifier (ID)and other information by receiving a primary synchronization channel(P-SCH) and a secondary synchronization channel (S-SCH) from the eNB.Then the UE may acquire information broadcast in the cell by receiving aphysical broadcast channel (PBCH) from the eNB. During the initial cellsearch, the UE may monitor a DL channel state by receiving a downlinkreference signal (DL RS).

After the initial cell search, the UE may acquire detailed systeminformation by receiving a physical downlink control channel (PDCCH) andreceiving a physical downlink shared channel (PDSCH) based oninformation included in the PDCCH (S202).

If the UE initially accesses the eNB or has no radio resources forsignal transmission to the eNB, the UE may perform a random accessprocedure with the eNB (S203 to S206). In the random access procedure,the UE may transmit a predetermined sequence as a preamble on a physicalrandom access channel (PRACH) (S203 and S205) and may receive a responsemessage to the preamble on a PDCCH and a PDSCH associated with the PDCCH(S204 and S206). In the case of a contention-based RACH, the UE mayadditionally perform a contention resolution procedure.

After the above procedure, the UE may receive a PDCCH and/or a PDSCHfrom the eNB (S207) and transmit a physical uplink shared channel(PUSCH) and/or a physical uplink control channel (PUCCH) to the eNB(S208), which is a general DL and UL signal transmission procedure.Particularly, the UE receives downlink control information (DCI) on aPDCCH. Herein, the DCI includes control information such as resourceallocation information for the UE. Different DCI formats are definedaccording to different usages of DCI.

Control information that the UE transmits to the eNB on the UL orreceives from the eNB on the DL includes a DL/UL acknowledgment/negativeacknowledgment (ACK/NACK) signal, a channel quality indicator (CQI), aprecoding matrix index (PMI), a rank indicator (RI), etc. In the 3GPPLTE system, the UE may transmit control information such as a CQI, aPMI, an RI, etc. on a PUSCH and/or a PUCCH.

An NR system considers a method using an ultra-high frequency band,i.e., a millimeter frequency band of 6 GHz or above, to transmit data tomultiple users using a wide frequency band while maintaining a hightransmission rate. In 3GPP, this is used by the name of NR and, in thepresent disclosure, this will be hereinafter referred to as the NRsystem.

The NR system uses OFDM or a similar transmission scheme. The NR systemmay operate based on OFDM parameters different from those used in LTE.Alternatively, the NR system may operate with a legacy LTE/LTE-Anumerology, but in a larger system bandwidth (e.g., 100 MHz) than inLTE/LTE-A. Alternatively, one or more cells may support a plurality ofnumerologies in the NR system. That is, UEs operating with differentnumerologies may coexist within one cell.

FIG. 3 illustrates a structure of a radio frame used in NR.

In NR, UL and DL transmissions are configured in frames. The radio framehas a length of 10 ms and is defined as two 5-ms half-frames (HFs). Thehalf-frame is defined as five 1-ms subframes (SFs). A subframe isdivided into one or more slots, and the number of slots in a subframedepends on subcarrier spacing (SCS). Each slot includes 12 or 14 OFDM(A)symbols according to a cyclic prefix (CP). When a normal CP is used,each slot includes 14 symbols. When an extended CP is used, each slotincludes 12 symbols. Here, the symbols may include OFDM symbols (orCP-OFDM symbols) and SC-FDMA symbols (or DFT-s-OFDM symbols).

Table 1 illustrates that the number of symbols per slot, the number ofslots per frame, and the number of slots per subframe vary according tothe SCS when the normal CP is used.

TABLE 1 SCS (15*2{circumflex over ( )}u) N^(slot) _(symb) N^(frame, u)_(slot) N^(subframe, u) _(slot) 15 KHz (u = 0) 14 10 1 30 KHz (u = 1) 1420 2 60 KHz (u = 2) 14 40 4 120 KHz (u = 3) 14 80 8 240 KHz (u = 4) 14160 16 *N^(slot) _(symb): Number of symbols in a slot *N^(frame, u)_(slot): Number of slots in a frame *N^(subframe, u) _(slot): Number ofslots in a subframe

Table 2 illustrates that the number of symbols per slot, the number ofslots per frame, and the number of slots per subframe vary according tothe SCS when the extended CP is used.

TABLE 2 SCS (15*2{circumflex over ( )}u) N^(slot) _(symb) N^(frame, u)_(slot) N^(subframe, u) _(slot) 60 KHz (u = 2) 12 40 4

In the NR system, the OFDM(A) numerology (e.g., SCS, CP length, etc.)may be configured differently among a plurality of cells merged for oneUE. Thus, the (absolute time) duration of a time resource (e.g., SF,slot or TTI) (referred to as a time unit (TU) for simplicity) composedof the same number of symbols may be set differently among the mergedcells.

FIG. 4 illustrates a slot structure of an NR frame. A slot includes aplurality of symbols in the time domain. For example, in the case of thenormal CP, one slot includes seven symbols. On the other hand, in thecase of the extended CP, one slot includes six symbols. A carrierincludes a plurality of subcarriers in the frequency domain. A resourceblock (RB) is defined as a plurality of consecutive subcarriers (e.g.,12 consecutive subcarriers) in the frequency domain. A bandwidth part(BWP) is defined as a plurality of consecutive (P)RBs in the frequencydomain and may correspond to one numerology (e.g., SCS, CP length,etc.). A carrier may include up to N (e.g., five) BWPs. Datacommunication is performed through an activated BWP, and only one BWPmay be activated for one UE. In the resource grid, each element isreferred to as a resource element (RE), and one complex symbol may bemapped thereto.

FIG. 5 illustrates a structure of a self-contained slot. In the NRsystem, a frame has a self-contained structure in which a DL controlchannel, DL or UL data, a UL control channel, and the like may all becontained in one slot. For example, the first N symbols (hereinafter, DLcontrol region) in the slot may be used to transmit a DL controlchannel, and the last M symbols (hereinafter, UL control region) in theslot may be used to transmit a UL control channel. N and M are integersgreater than or equal to 0. A resource region (hereinafter, a dataregion) that is between the DL control region and the UL control regionmay be used for DL data transmission or UL data transmission. Forexample, the following configuration may be considered. Respectivesections are listed in a temporal order.

1. DL only configuration

2. UL only configuration

3. Mixed UL-DL configuration

-   -   DL region+Guard period (GP)+UL control region    -   DL control region+GP+UL region    -   DL region: (i) DL data region, (ii) DL control region+DL data        region    -   UL region: (i) UL data region, (ii) UL data region+UL control        region

The PDCCH may be transmitted in the DL control region, and the PDSCH maybe transmitted in the DL data region. The PUCCH may be transmitted inthe UL control region, and the PUSCH may be transmitted in the UL dataregion. Downlink control information (DCI), for example, DL datascheduling information, UL data scheduling information, and the like,may be transmitted on the PDCCH. Uplink control information (UCI), forexample, ACK/NACK information about DL data, channel state information(CSI), and a scheduling request (SR), may be transmitted on the PUCCH.The GP provides a time gap in the process of the UE switching from thetransmission mode to the reception mode or from the reception mode tothe transmission mode. Some symbols at the time of switching from DL toUL within a subframe may be configured as the GP.

FIG. 6 illustrates an SSB structure. The UE may perform cell search,system information acquisition, beam alignment for initial access, DLmeasurement, etc. based on the SSB. The SSB and synchronizationsignal/physical broadcast channel (SS/PBCH) block are interchangeablyused.

Referring to FIG. 6, an SSB includes a PSS, an SSS, and a PBCH. The SSBis configured over four consecutive OFDM symbols, and the PSS, PBCH,SSS/PBCH, and PBCH are transmitted on the respective OFDM symbols. ThePSS and SSS may each consist of 1 OFDM symbol and 127 subcarriers, andthe PBCH may consist of 3 OFDM symbols and 576 subcarriers. Polar codingand quadrature phase shift keying (QPSK) are applied to the PBCH. ThePBCH may have a data RE and a demodulation reference signal (DMRS) REfor each OFDM symbol. There may be three DMRS REs for each RB, and theremay be three data REs between DMRS REs.

The cell search refers to a procedure in which the UE acquirestime/frequency synchronization of a cell and detects a cell ID (e.g.,physical layer cell ID (PCID)) of the cell. The PSS may be used indetecting a cell ID within a cell ID group, and the SSS may be used indetecting a cell ID group. The PBCH may be used in detecting an SSB(time) index and a half-frame.

The cell search procedure of the UE may be summarized as shown in Table3 below.

TABLE 3 Type of Signals Operations 1^(st) step PSS * SS/PBCH block (SSB)symbol timing acquisition * Cell ID detection within a cell ID group (3hypothesis) 2^(nd) Step SSS * Cell ID group detection (336 hypothesis)3^(rd) Step PBCH DMRS * SSB index and Half frame (HF) index (Slot andframe boundary detection) 4^(th) Step PBCH * Time information (80 ms,System Frame Number (SFN), SSB index, HF) * Remaining Minimum SystemInformation (RMSI) Control resource set (CORESET)/ Search spaceconfiguration 5^(th) Step PDCCH and * Cell access information * RACHPDSCH configuration

There may be 336 cell ID groups, and each cell ID group may have threecell IDs. There may be 1008 cell IDs in total. Information about a cellID group to which a cell ID of a cell belongs may be provided/acquiredthrough the SSS of the cell, and information about the cell ID among 336cells in the cell ID may be provided/acquired through the PSS.

FIG. 7 illustrates SSB transmission. Referring to FIG. 7, the SSB isperiodically transmitted in accordance with the SSB periodicity. Thebasic SSB periodicity assumed by the UE in the initial cell search isdefined as 20 ms. After cell access, the SSB periodicity may be set toone of {5 ms, 10 ms, 20 ms, 40 ms, 80 ms, 160 ms} by the network (e.g.,the BS). A SSB burst set may be configured at the beginning of the SSBperiodicity. The SSB burst set may be configured with a 5 ms time window(i.e., half-frame), and the SSB may be repeatedly transmitted up to Ltimes within the SS burst set. The maximum number of transmissions ofthe SSB, L, may be given according to the frequency band of the carrierwave as follows. One slot includes up to two SSBs.

-   -   For frequency range up to 3 GHz, L=4    -   For frequency range from 3 GHz to 6 GHz, L=8    -   For frequency range from 6 GHz to 52.6 GHz, L=64

The time position of an SSB candidate in the SS burst set may be definedaccording to the SCS as follows. The time position of the SSB candidateis indexed from 0 to L−1 in temporal order within the SSB burst set(i.e., half-frame) (SSB index).

-   -   Case A—15 kHz SCS: The index of the start symbol of a candidate        SSB is given as {2, 8}+14*n. When the carrier frequency is lower        than or equal to 3 GHz, n=0, 1. When the carrier frequency is 3        GHz to 6 GHz, n=0, 1, 2, 3.    -   Case B—30 kHz SCS: The index of the start symbol of a candidate        SSB is given as {4, 8, 16, 20}+28*n. When the carrier frequency        is lower than or equal to 3 GHz, n=0. When the carrier frequency        is 3 GHz to 6 GHz, n=0, 1.    -   Case C—30 kHz SCS: The index of the start symbol of a candidate        SSB is given as {2, 8}+14*n. When the carrier frequency is lower        than or equal to 3 GHz, n=0. When the carrier frequency is 3 GHz        to 6 GHz, n=0, 1, 2, 3.    -   Case D—120 kHz SCS: The index of the start symbol of a candidate        SSB is given as {4, 8, 16, 20}+28*n. When the carrier frequency        is higher than 6 GHz, n=0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13,        15, 16, 17, 18.    -   Case E—240 kHz SCS: The index of the start symbol of a candidate        SSB is given as {8, 12, 16, 20, 32, 36, 40, 44}+56*n. When the        carrier frequency is higher than 6 GHz, n=0, 1, 2, 3, 5, 6, 7,        8.

CSI-Related Behavior

In a new radio (NR) system, a CSI-RS is used for time and/or frequencytracking, CSI computation, RSRP calculation, and mobility. Here, CSIcomputation is related to CSI acquisition, and RSRP computation isrelated to beam management (BM).

FIG. 8 is a flowchart illustrating an exemplary CSI related procedure.

-   -   To perform one of the above purposes of the CSI-RS, the UE        receives configuration information related to CSI from the BS        through RRC signaling (S801).

The CSI related configuration information may include at least one ofCSI-interference management (IM) resource related information, CSImeasurement configuration related information, CSI resourceconfiguration related information, CSI-RS resource related information,or CSI report configuration related information.

i) The CSI-IM resource related information may include CSI-IM resourceinformation, CSI-IM resource set information, etc. A CSI-IM resource setis identified by a CSI-IM resource set identifier (ID), and one resourceset includes at least one CSI-IM resource. Each CSI-IM resource isidentified by a CSI-IM resource ID.

ii) The CSI resource configuration related information may be expressedas a CSI-ResourceConfig information element (IE). The CSI resourceconfiguration related information defines a group including at least oneof a non-zero power (NZP) CSI-RS resource set, a CSI-IM resource set, ora CSI-SSB resource set. That is, the CSI resource configuration relatedinformation includes a CSI-RS resource set list. The CSI-RS resource setlist may include at least one of an NZP CSI-RS resource set list, aCSI-IM resource set list, or a CSI-SSB resource set list. The CSI-RSresource set is identified by a CSI-RS resource set ID, and one resourceset includes at least one CSI-RS resource. Each CSI-RS resource isidentified by a CSI-RS resource ID.

RRC parameters (e.g., a BM related “repetition” parameter and a trackingrelated “trs-Info” parameter) indicating usage of a CSI-RS for each NZPCSI-RS resource set may be configured.

iii) The CSI report configuration related information includes a reportconfiguration type parameter (reportConfigType) indicative of a timedomain behavior and a report quantity parameter (reportQuantity)indicative of a CSI related quantity to be reported. The time domainbehavior may be periodic, aperiodic, or semi-persistent.

-   -   The UE measures CSI based on the CSI related configuration        information (S803). Measuring the CSI may include (1) receiving        a CSI-RS by the UE (S805) and (2) computing the CSI based on the        received CSI-RS (S807). For the CSI-RS, RE mapping of CSI-RS        resources is configured in time and frequency domains by an RRC        parameter CSI-RS-ResourceMapping.    -   The UE reports the measured CSI to the BS (S809).

1. CSI Measurement

The NR system supports more flexible and dynamic CSI measurement andreporting. The CSI measurement may include receiving a CSI-RS, andacquiring CSI by computing the received CSI-RS.

As time domain behaviors of CSI measurement and reporting, channelmeasurement (CM) and interference measurement (IM) are supported.

A CSI-IM-based interference measurement resource (IMR) of NR has adesign similar to CSI-IM of LTE and is configured independent of ZPCSI-RS resources for PDSCH rate matching.

At each port of a configured NZP CSI-RS-based IMR, the BS transmits anNZP CSI-RS to the UE.

If there is no PMI or RI feedback for a channel, a plurality ofresources is configured in a set and the BS or network indicates,through DCI, a subset of NZP CSI-RS resources for CM/IM.

Resource setting and resource setting configuration will be described inmore detail.

1.1. Resource Setting

Each CSI resource setting “CSI-ResourceConfig” includes configuration ofS(≥1) CSI resource sets (which are given by RRC parametercsi-RS-ResourceSetList). A CSI resource setting corresponds toCSI-RS-resourcesetlist. Here, S represents the number of configuredCSI-RS resource sets. Configuration of S(≥1) CSI resource sets includeseach CSI resource set including CSI-RS resources (composed of NZP CSI-RSor CSI-IM), and an SS/PBCH block (SSB) resource used for RSRPcomputation.

Each CSI resource setting is positioned at a DL bandwidth part (BWP)identified by RRC parameter bwp-id. All CSI resource settings linked toa CSI reporting setting have the same DL BWP.

In a CSI resource setting included in a CSI-ResourceConfig IE, a timedomain behavior of a CSI-RS resource may be indicated by RRC parameterresourceType and may be configured to be aperiodic, periodic, orsemi-persistent.

One or more CSI resource settings for CM and IM are configured throughRRC signaling. A channel measurement resource (CMR) may be an NZP CSI-RSfor CSI acquisition, and an interference measurement resource (IMR) maybe an NZP CSI-RS for CSI-IM and for IM. Here, CSI-IM (or a ZP CSI-RS forIM) is mainly used for inter-cell interference measurement. An NZPCSI-RS for IM is mainly used for intra-cell interference measurementfrom multiple users.

The UE may assume that CSI-RS resource(s) for CM and CSI-IM/NZP CSI-RSresource(s) for IM configured for one CSI reporting are “QCL-TypeD” foreach resource.

1.2. Resource Setting Configuration

A resource setting may represent a resource set list.

-   -   When one resource setting is configured, a resource setting        (given by RRC parameter resourcesForChannelMeasurement) is about        channel measurement for RSRP computation.    -   When two resource settings are configured, the first resource        setting (given by RRC parameter resourcesForChannelMeasurement)        is for channel measurement and the second resource setting        (given by csi-IM-ResourcesForInterference or        nzp-CSI-RS-ResourcesForInterference) is for CSI-IM or for        interference measurement performed on an NZP CSI-RS.    -   When three resource settings are configured, the first resource        setting (given by resourcesForChannelMeasurement) is for channel        measurement, the second resource setting (given by        csi-IM-ResourcesForInterference) is for CSI-IM based        interference measurement, and the third resource setting (given        by nzp-CSI-RS-ResourcesForInterference) is for NZP CSI-RS based        interference measurement.    -   When one resource setting (given by        resourcesForChannelMeasurement) is configured, the resource        setting is about channel measurement for RSRP computation.    -   When two resource settings are configured, the first resource        setting (given by resourcesForChannelMeasurement) is for channel        measurement, and the second resource setting (given by RRC        parameter csi-IM-ResourcesForInterference) is used for        interference measurement performed on CSI-IM.

1.3. CSI Computation

If interference measurement is performed on CSI-IM, each CSI-RS resourcefor channel measurement is associated with a CSI-RS resource in order ofCSI-RS resources and CSI-IM resources in a corresponding resource set.The number of CSI-RS resources for channel measurement is the same asthe number of CSI-IM resources.

For CSI measurement, the UE assumes the following.

-   -   Each NZP CSI-RS port configured for interference measurement        corresponds to an interference transmission layer.    -   Every interference transmission layer of NZP CSI-RS ports for        interference measurement considers an energy per resource        element (EPRE) ratio.    -   Different interference signals are assumed on RE(s) of an NZP        CSI-RS resource for channel measurement, an NZP CSI-RS resource        for interference measurement, or a CSI-IM resource for        interference measurement.

2. CSI Reporting

For CSI reporting, time and frequency resources available for the UE arecontrolled by the BS.

Regarding a CQI, PMI, CSI-RS resource indicator (CRI), SS/PBCH blockresource indicator (SSBRI), layer indicator (LI), RI, or L1-RSRP, the UEreceives RRC signaling including N(≥1) CSI-ReportConfig reportingsettings, M(≥1) CSI-ResourceConfig resource settings, and a list of oneor two trigger states (provided by aperiodicTriggerStateList andsemiPersistentOnPUSCH-TriggerStateList). In aperiodicTriggerStateList,each trigger state includes a channel and optionally a list ofassociated CSI-ReportConfigs indicative of resource set IDs forinterference. In semiPersistentOnPUSCH-TriggerStateList, each triggerstate includes one associated CSI-ReportConfig.

That is, for each CSI-RS resource setting, the UE transmits CSIreporting indicated by CSI-ReportConfigs associated with the CSI-RSresource setting to the BS. For example, the UE may report at least oneof the CQI, PMI, CRI, SSBRI, LI, RI, or RSRP as indicated byCSI-ReportConfigs associated with the CSI resource setting. However, ifCSI-ReportConfigs associated with the CSI resource setting indicates“none”, the UE may skip reporting of the CSI or RSRP associated with theCSI resource setting. The CSI resource setting may include a resourcefor an SS/PBCH block.

Positioning Reference Signal (PRS) in LTE System

Positioning may refer to determining the geographical position and/orvelocity of the UE based on measurement of radio signals. Locationinformation may be requested by and reported to a client (e.g., anapplication) associated with to the UE. The location information mayalso be requested by a client within or connected to a core network. Thelocation information may be reported in standard formats such as formatsfor cell-based or geographical coordinates, together with estimatederrors of the position and velocity of the UE and/or a positioningmethod used for positioning.

For such positioning, a positioning reference signal (PRS) may be used.The PRS is a reference signal used to estimate the position of the UE.For example, in the LTE system, the PRS may be transmitted only in a DLsubframe configured for PRS transmission (hereinafter, “positioningsubframe”). If both a multimedia broadcast single frequency network(MBSFN) subframe and a non-MBSFN subframe are configured as positioningsubframes, OFDM symbols of the MBSFN subframe should have the samecyclic prefix (CP) as subframe #0. If only MBSFN subframes areconfigured as the positioning subframes within a cell, OFDM symbolsconfigured for the PRS in the MBSFN subframes may have an extended CP.

The sequence of the PRS may be defined by Equation 1 below.

$\begin{matrix}{{{r_{l,n_{s}}(m)} = {{\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {2m} \right)}}} \right)} + {j\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {{2m} + 1} \right)}}} \right)}}},\mspace{79mu}{m = 0},1,\ldots\mspace{14mu},{{2N_{RB}^{\max,{DL}}} - 1}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

In Equation 1, n_(s) denotes a slot number in a radio frame and 1denotes an OFDM symbol number in a slot. N_(RB) ^(max,DL) is the largestof DL bandwidth configurations, expressed as N_(SC) ^(RB). N_(SC) ^(RB)denotes the size of an RB in the frequency domain, for example, 12subcarriers.

c(i) denotes a pseudo-random sequence and may be initialized by Equation2 below.c _(init)=2²⁸ ·└N _(ID) ^(PRS)/512┘+2¹⁰·(7·(n _(s)+1)+l+1)·(2·(N _(ID)^(PRS) mod 512)+1)+2·(N _(ID) ^(PRS) mod 512)+N _(CP)  Equation 2

Unless additionally configured by higher layers, N_(ID) ^(PRS) is equalto N_(ID) ^(cell), and N_(CP) is 1 for a normal CP and 0 for an extendedCP.

FIGS. 9A and 9B illustrate an exemplary pattern to which a PRS is mappedin a subframe. As illustrated in FIGS. 9A and 9B, the PRS may betransmitted through an antenna port 6. FIG. 9A illustrates mapping ofthe PRS in the normal CP and FIG. 9B illustrates mapping of the PRS inthe extended CP.

The PRS may be transmitted in consecutive subframes grouped for positionestimation. The subframes grouped for position estimation are referredto as a positioning occasion. The positioning occasion may consist of 1,2, 4 or 6 subframe. The positioning occasion may occur periodically witha periodicity of 160, 320, 640 or 1280 subframes. A cell-specificsubframe offset value may be defined to indicate the starting subframeof PRS transmission. The offset value and the periodicity of thepositioning occasion for PRS transmission may be derived from a PRSconfiguration index as listed in Table 4 below.

TABLE 4 PRS configuration PRS periodicity PRS subframe offset Index(I_(PRS)) (subframes) (subframes)  0-159 160 I_(PRS) 160-479 320I_(PRS)-160   480-1119 640 I_(PRS)-480  1120-2399 1280 I_(PRS)-11202400-2404 5 I_(PRS)-2400 2405-2414 10 I_(PRS)-2405 2415-2434 20I_(PRS)-2415 2435-2474 40 I_(PRS)-2435 2475-2554 80 I_(PRS)-24752555-4095 Reserved

A PRS included in each positioning occasion is transmitted with constantpower. A PRS in a certain positioning occasion may be transmitted withzero power, which is referred to as PRS muting. For example, when a PRStransmitted by a serving cell is muted, the UE may easily detect a PRSof a neighbor cell.

The PRS muting configuration of a cell may be defined by a periodicmuting sequence consisting of 2, 4, 8 or 16 positioning occasions. Thatis, the periodic muting sequence may include 2, 4, 8, or 16 bitsaccording to a positioning occasion corresponding to the PRS mutingconfiguration and each bit may have a value “0” or “1”. For example, PRSmuting may be performed in a positioning occasion with a bit value of“0”.

The positioning subframe is designed as a low-interference subframe sothat no data is transmitted in the positioning subframe. Therefore, thePRS is not subjected to interference due to data transmission althoughthe PRS may interfere with PRSs of other cells.

UE Positioning Architecture in NR System

FIG. 10 illustrates architecture of a 5G system applicable topositioning of a UE connected to an NG-RAN or an E-UTRAN.

Referring to FIG. 10, an AMF may receive a request for a locationservice associated with a particular target UE from another entity suchas a gateway mobile location center (GMLC) or the AMF itself decides toinitiate the location service on behalf of the particular target UE.Then, the AMF transmits a request for a location service to a locationmanagement function (LMF). Upon receiving the request for the locationservice, the LMF may process the request for the location service andthen returns the processing result including the estimated position ofthe UE to the AMF. In the case of a location service requested by anentity such as the GMLC other than the AMF, the AMF may transmit theprocessing result received from the LMF to this entity.

A new generation evolved-NB (ng-eNB) and a gNB are network elements ofthe NG-RAN capable of providing a measurement result for positioning.The ng-eNB and the gNB may measure radio signals for a target UE andtransmits a measurement result value to the LMF. The ng-eNB may controlseveral TPs, such as remote radio heads, or PRS-only TPs for support ofa PRS-based beacon system for E-UTRA.

The LMF is connected to an enhanced serving mobile location center(E-SMLC) which may enable the LMF to access the E-UTRAN. For example,the E-SMLC may enable the LMF to support OTDOA, which is one ofpositioning methods of the E-UTRAN, using DL measurement obtained by atarget UE through signals transmitted by eNBs and/or PRS-only TPs in theE-UTRAN.

The LMF may be connected to an SUPL location platform (SLP). The LMF maysupport and manage different location services for target UEs. The LMFmay interact with a serving ng-eNB or a serving gNB for a target UE inorder to obtain position measurement for the UE. For positioning of thetarget UE, the LMF may determine positioning methods, based on alocation service (LCS) client type, required quality of service (QoS),UE positioning capabilities, gNB positioning capabilities, and ng-eNBpositioning capabilities, and then apply these positioning methods tothe serving gNB and/or serving ng-eNB. The LMF may determine additionalinformation such as accuracy of the location estimate and velocity ofthe target UE. The SLP is a secure user plane location (SUPL) entityresponsible for positioning over a user plane.

The UE may measure the position thereof using DL RSs transmitted by theNG-RAN and the E-UTRAN. The DL RSs transmitted by the NG-RAN and theE-UTRAN to the UE may include a SS/PBCH block, a CSI-RS, and/or a PRS.Which DL RS is used to measure the position of the UE may conform toconfiguration of LMF/E-SMLC/ng-eNB/E-UTRAN etc. The position of the UEmay be measured by an RAT-independent scheme using different globalnavigation satellite systems (GNSSs), terrestrial beacon systems (TBSs),WLAN access points, Bluetooth beacons, and sensors (e.g., barometricsensors) installed in the UE. The UE may also contain LCS applicationsor access an LCS application through communication with a networkaccessed thereby or through another application contained therein. TheLCS application may include measurement and calculation functions neededto determine the position of the UE. For example, the UE may contain anindependent positioning function such as a global positioning system(GPS) and report the position thereof, independent of NG-RANtransmission. Such independently obtained positioning information may beused as assistance information of positioning information obtained fromthe network.

Operation for UE Positioning

FIG. 11 illustrates an implementation example of a network for UEpositioning. When an AMF receives a request for a location service inthe case in which the UE is in connection management (CM)-IDLE state,the AMF may make a request for a network triggered service in order toestablish a signaling connection with the UE and to assign a specificserving gNB or ng-eNB. This operation procedure is omitted in FIG. 11.In other words, in FIG. 11, it may be assumed that the UE is in aconnected mode. However, the signaling connection may be released by anNG-RAN as a result of signaling and data inactivity while a positioningprocedure is still ongoing.

An operation procedure of the network for UE positioning will now bedescribed in detail with reference to FIG. 11. In step 1 a, a 5GC entitysuch as GMLC may transmit a request for a location service for measuringthe position of a target UE to a serving AMF. Here, even when the GMLCdoes not make the request for the location service, the serving AMF maydetermine the need for the location service for measuring the positionof the target UE according to step 1 b. For example, the serving AMF maydetermine that itself will perform the location service in order tomeasure the position of the UE for an emergency call.

In step 2, the AMF transfers the request for the location service to anLMF. In step 3 a, the LMF may initiate location procedures with aserving ng-eNB or a serving gNB to obtain location measurement data orlocation measurement assistance data. For example, the LMF may transmita request for location related information associated with one or moreUEs to the NG-RAN and indicate the type of necessary locationinformation and associated QoS. Then, the NG-RAN may transfer thelocation related information to the LMF in response to the request. Inthis case, when a location determination method according to the requestis an enhanced cell ID (E-CID) scheme, the NG-RAN may transferadditional location related information to the LMF in one or more NRpositioning protocol A (NRPPa) messages. Here, the “location relatedinformation” may mean all values used for location calculation such asactual location estimate information and radio measurement or locationmeasurement. Protocol used in step 3 a may be an NRPPa protocol whichwill be described later.

Additionally, in step 3 b, the LMF may initiate a location procedure forDL positioning together with the UE. For example, the LMF may transmitthe location assistance data to the UE or obtain a location estimate orlocation measurement value. For example, in step 3 b, a capabilityinformation transfer procedure may be performed. Specifically, the LMFmay transmit a request for capability information to the UE and the UEmay transmit the capability information to the LMF. Here, the capabilityinformation may include information about a positioning methodsupportable by the LFM or the UE, information about various aspects of aparticular positioning method, such as various types of assistance datafor an A-GNSS, and information about common features not specific to anyone positioning method, such as ability to handle multiple LPPtransactions. In some cases, the UE may provide the capabilityinformation to the LMF although the LMF does not transmit a request forthe capability information.

As another example, in step 3 b, a location assistance data transferprocedure may be performed. Specifically, the UE may transmit a requestfor the location assistance data to the LMF and indicate particularlocation assistance data needed to the LMF. Then, the LMF may transfercorresponding location assistance data to the UE and transfer additionalassistance data to the UE in one or more additional LTE positioningprotocol (LPP) messages. The location assistance data delivered from theLMF to the UE may be transmitted in a unicast manner. In some cases, theLMF may transfer the location assistance data and/or the additionalassistance data to the UE without receiving a request for the assistancedata from the UE.

As another example, in step 3 b, a location information transferprocedure may be performed. Specifically, the LMF may send a request forthe location (related) information associated with the UE to the UE andindicate the type of necessary location information and associated QoS.In response to the request, the UE may transfer the location relatedinformation to the LMF. Additionally, the UE may transfer additionallocation related information to the LMF in one or more LPP messages.Here, the “location related information” may mean all values used forlocation calculation such as actual location estimate information andradio measurement or location measurement. Typically, the locationrelated information may be a reference signal time difference (RSTD)value measured by the UE based on DL RSs transmitted to the UE by aplurality of NG-RANs and/or E-UTRANs. Similarly to the abovedescription, the UE may transfer the location related information to theLMF without receiving a request from the LMF.

The procedures implemented in step 3 b may be performed independentlybut may be performed consecutively. Generally, although step 3 b isperformed in order of the capability information transfer procedure, thelocation assistance data transfer procedure, and the locationinformation transfer procedure, step 3 b is not limited to such order.In other words, step 3 b is not required to occur in specific order inorder to improve flexibility in positioning. For example, the UE mayrequest the location assistance data at any time in order to perform aprevious request for location measurement made by the LMF. The LMF mayalso request location information, such as a location measurement valueor a location estimate value, at any time, in the case in which locationinformation transmitted by the UE does not satisfy required QoS.Similarly, when the UE does not perform measurement for locationestimation, the UE may transmit the capability information to the LMF atany time.

In step 3 b, when information or requests exchanged between the LMF andthe UE are erroneous, an error message may be transmitted and receivedand an abort message for aborting positioning may be transmitted andreceived.

Protocol used in step 3 b may be an LPP protocol which will be describedlater.

Step 3 b may be performed additionally after step 3 a but may beperformed instead of step 3 a.

In step 4, the LMF may provide a location service response to the AMF.The location service response may include information as to whether UEpositioning is successful and include a location estimate value of theUE. If the procedure of FIG. 10 has been initiated by step 1 a, the AMFmay transfer the location service response to a 5GC entity such as aGMLC. If the procedure of FIG. 10 has been initiated by step 1 b, theAMF may use the location service response in order to provide a locationservice related to an emergency call.

Positioning Protocol

(1) LTE Positioning Protocol (LPP)

FIG. 12 illustrates an exemplary protocol layer used to support LPPmessage transfer between an LMF and a UE. An LPP protocol data unit(PDU) may be carried in a NAS PDU between an AMF and the UE. Referringto FIG. 12, LPP is terminated between a target device (e.g., a UE in acontrol plane or an SUPL enabled terminal (SET) in a user plane) and alocation server (e.g., an LMF in the control plane or an SLP in the userplane). LPP messages may be carried as transparent PDUs crossintermediate network interfaces using appropriate protocols, such anNGAP over an NG-C interface and NAS/RRC over LTE-Uu and NR-Uuinterfaces. LPP is intended to enable positioning for NR and LTE usingvarious positioning methods.

For example, a target device and a location server may exchange, throughLPP, capability information therebetween, assistance data forpositioning, and/or location information. The target device and thelocation server may exchange error information and/or indicate abort ofan LPP procedure, through an LPP message.

(2) NR Positioning Protocol a (NRPPa)

FIG. 13 illustrates an exemplary protocol layer used to support NRPPaPDU transfer between an LMF and an NG-RAN node. NRPPa may be used tocarry information between an NG-RAN node and an LMF. Specifically, NRPPamay carry an E-CID for measurement transferred from an ng-eNB to an LMF,data for support of an OTDOA positioning method, and a cell-ID and acell position ID for support of an NR cell ID positioning method. An AMFmay route NRPPa PDUs based on a routing ID of an involved LMF over anNG-C interface without information about related NRPPa transaction.

An NRPPa procedure for location and data collection may be divided intotwo types. The first type is a UE associated procedure for transfer ofinformation about a particular UE (e.g., location measurementinformation) and the second type is a non-UE-associated procedure fortransfer of information applicable to an NG-RAN node and associated TPs(e.g., gNB/ng-eNB/TP timing information). The two types may be supportedindependently or may be supported simultaneously.

Positioning Method

Positioning methods supported in the NG-RAN may include a GNSS, anOTDOA, an E-CID, barometric sensor positioning, WLAN positioning,Bluetooth positioning, a TBS, uplink time difference of arrival (UTDOA)etc. Although any one of the positioning methods may be used for UEpositioning, two or more positioning methods may be used for UEpositioning.

(1) Observed Time Difference of Arrival (OTDOA)

FIG. 14 is a view illustrating an OTDOA positioning method. The OTDOApositioning method uses time measured for DL signals received frommultiple TPs including an eNB, an ng-eNB, and a PRS-only TP by the UE.The UE measures time of received DL signals using location assistancedata received from a location server. The position of the UE may bedetermined based on such a measurement result and geographicalcoordinates of neighboring TPs.

The UE connected to the gNB may request measurement gaps to performOTDOA measurement from a TP. If the UE is not aware of an SFN of atleast one TP in OTDOA assistance data, the UE may use autonomous gaps toobtain an SFN of an OTDOA reference cell prior to requesting measurementgaps for performing reference signal time difference (RSTD) measurement.

Here, the RSTD may be defined as the smallest relative time differencebetween two subframe boundaries received from a reference cell and ameasurement cell. That is, the RSTD may be calculated as the relativetime difference between the start time of a subframe received from themeasurement cell and the start time of a subframe from the referencecell that is closest to the subframe received from the measurement cell.The reference cell may be selected by the UE.

For accurate OTDOA measurement, it is necessary to measure time ofarrival (ToA) of signals received from geographically distributed threeor more TPs or BSs. For example, ToA for each of TP 1, TP 2, and TP 3may be measured, and RSTD for TP 1 and TP 2, RSTD for TP 2 and TP 3, andRSTD for TP 3 and TP 1 are calculated based on three ToA values. Ageometric hyperbola is determined based on the calculated RSTD valuesand a point at which curves of the hyperbola cross may be estimated asthe position of the UE. In this case, accuracy and/or uncertainty foreach ToA measurement may occur and the estimated position of the UE maybe known as a specific range according to measurement uncertainty.

For example, RSTD for two TPs may be calculated based on Equation 3below.

                                      Equation  3${RSTDi},{1 = {\frac{\sqrt{\left( {x_{t} - x_{i}} \right)^{2} + \left( {y_{t} - y_{i}} \right)^{2}}}{c} - \frac{\sqrt{\left( {x_{t} - x_{1}} \right)^{2} + \left( {y_{t} - y_{1}} \right)^{2}}}{c} + \left( {{Ti} - {T1}} \right) + \left( {{ni} - {n\; 1}} \right)}}$

In Equation 3, c is the speed of light, {x_(t), y_(t)} are (unknown)coordinates of a target UE, {x_(i), y_(i)} are (known) coordinates of aTP, and {x₁, y₁} are coordinates of a reference TP (or another TP).Here, (T_(i)−T₁) is a transmission time offset between two TPs, referredto as “real time differences” (RTDs), and n_(i) and n₁ are UE ToAmeasurement error values.

(2) Enhanced Cell ID (E-CID)

In a cell ID (CID) positioning method, the position of the UE may bemeasured based on geographical information of a serving ng-eNB, aserving gNB, and/or a serving cell of the UE. For example, thegeographical information of the serving ng-eNB, the serving gNB, and/orthe serving cell may be acquired by paging, registration, etc.

The E-CID positioning method may use additional UE measurement and/orNG-RAN radio resources in order to improve UE location estimation inaddition to the CID positioning method. Although the E-CID positioningmethod partially may utilize the same measurement methods as ameasurement control system on an RRC protocol, additional measurementonly for UE location measurement is not generally performed. In otherwords, an additional measurement configuration or measurement controlmessage may not be provided for UE location measurement. The UE does notexpect that an additional measurement operation only for locationmeasurement will be requested and the UE may report a measurement valueobtained by generally measurable methods.

For example, the serving gNB may implement the E-CID positioning methodusing an E-UTRA measurement value provided by the UE.

Measurement elements usable for E-CID positioning may be, for example,as follows.

-   -   UE measurement: E-UTRA reference signal received power (RSRP),        E-UTRA reference signal received quality (RSRQ), UE E-UTRA        reception (Rx)-transmission (Tx) time difference, GERAN/WLAN        reference signal strength indication (RSSI), UTRAN common pilot        channel (CPICH) received signal code power (RSCP), and/or UTRAN        CPICH Ec/Io    -   E-UTRAN measurement: ng-eNB Rx-Tx time difference, timing        advance (T_(ADV)), and/or AoA

Here, T_(ADV) may be divided into Type 1 and Type 2 as follows.

T_(ADV) Type 1=(ng-eNB Rx-Tx time difference)+(UE E-UTRA Rx-Tx timedifference)

T_(ADV) Type 2=ng-eNB Rx-Tx time difference

AoA may be used to measure the direction of the UE. AoA is defined asthe estimated angle of the UE counterclockwise from the eNB/TP. In thiscase, a geographical reference direction may be north. The eNB/TP mayuse a UL signal such as an SRS and/or a DMRS for AoA measurement. Theaccuracy of measurement of AoA increases as the arrangement of anantenna array increases. When antenna arrays are arranged at the sameinterval, signals received at adjacent antenna elements may haveconstant phase rotate.

(3) Uplink Time Difference of Arrival (UTDOA)

UTDOA is to determine the position of the UE by estimating the arrivaltime of an SRS. When an estimated SRS arrival time is calculated, aserving cell is used as a reference cell and the position of the UE maybe estimated by the arrival time difference with another cell (or aneNB/TP). To implement UTDOA, an E-SMLC may indicate the serving cell ofa target UE in order to indicate SRS transmission to the target UE. TheE-SMLC may provide configurations such as periodic/non-periodic SRS,bandwidth, and frequency/group/sequence hopping.

When only one PRS (e.g., PRS ID) is assigned to a specific TP/BSsupporting an NR system based on multiple narrow Tx beams, a UE may havedifficulty in distinguishing PRSs transmitted on different Tx beams fromeach other. Further, when different bandwidth configurations are appliedto PRSs in spite of the same Tx beam used for the PRSs, the computationcomplexity of the UE may be reduced. In this context, the following PRSresource and PRS resource set configurations will be described.

FIGS. 15 to 18 are diagrams illustrating implementation examples ofoperations of a UE, a BS, a location server, and a network according toembodiments of the present disclosure.

With reference to FIG. 15, a schematic operational implementationexample of the BS will be described. Referring to FIG. 15, the BS mayconfigure PRS resources (S1501). The BS may receive information about aPRS resource configuration from the location server and configure thePRS resources based on the information about the PRS resourceconfiguration. A specific method of configuring PRS resources may bebased on embodiments which will be described later. The BS may transmitat least one of a PRS, an SS/PBCH block, or a CSI-RS to the UE (S1503).The BS may receive a report related to the at least one of the PRS, theSS/PBCH block, or the CSI-RS (S1505). Specific information included inthe report and a specific method of transmitting the report by the UEmay be based on embodiments which will be described later. Before stepS1501, the BS may transmit, to the location server, informationincluding a notification of using an SS/PBCH block and/or a CSI-RS asPRS resources or for the purpose of determining a Tx/Rx beam fortransmitting/receiving PRS resources.

The BS illustrated in FIG. 15 may be one of various wireless devicesillustrated in FIGS. 29 to 32. In other words, the operation of the BSillustrated in FIG. 15 may be performed by one of the various wirelessdevices illustrated in FIGS. 29 to 32.

With reference to FIG. 16, a schematic operational implementationexample of the UE will be described. Referring to FIG. 16, the UE mayreceive information related to a PRS resource configuration from the BSor the location server (S1601). Specific embodiments of the informationrelated to a PRS resource configuration will be described later.

The UE may receive at least one of a PRS, an SS/PBCH block, or a CSI-RSfrom the BS (S1603). The UE may transmit a report related to the atleast one of the PRS, the SS/PBCH block, or the CSI-RS (S1605). Specificinformation included in the report and a specific method of transmittingthe report by the UE may be based on the embodiments which will bedescribed later.

The UE illustrated in FIG. 16 may be one of the various wireless devicesillustrated in FIGS. 29 to 32. In other words, the operation of the UEillustrated in FIG. 16 may be performed by one of the various wirelessdevices illustrated in FIGS. 29 to 32.

FIG. 17 illustrates a schematic operational implementation example ofthe location server. Referring to FIG. 17, the location server maytransmit PRS resource configuration information to the BS and/or the UE(S1701). A specific method of configuring PRS resources may be based onthe embodiments which will be described later. The location server mayreceive a report related to at least one of a PRS, an SS/PBCH block, ora CSI-RS from the UE or the BS (S1703). Specific information included inthe report and a specific method of transmitting the report by the UE orthe BS may be based on the embodiments which will be described later.Before step S1701, the location server may receive, from the BS,information including a notification of using an SS/PBCH block and/or aCSI-RS as PRS resources or for the purpose of determining a Tx/Rx beamfor transmitting/receiving PRS resources.

The location server illustrated in FIG. 17 may be a device illustratedin FIG. 33. In other words, the operation of the location serverillustrated in FIG. 17 may be performed by the device illustrated inFIG. 33.

With reference to FIG. 18, a schematic operational implementationexample in the network will be described.

Referring to FIG. 18, the BS may transmit, to the location server,information including a notification of using an SS/PBCH block and/or aCSI-RS as PRS resources or for the purpose of determining a Tx/Rx beamfor transmitting/receiving PRS resources (S1800). The location servermay transmit PRS resource configuration information to the BS and/or theUE, and the BS may transmit the PRS resource configuration to the UE(S1801 to S1805). If the location server transmits the PRS resourceconfiguration information to both the BS and the UE, the BS may notperform step S1803. That is, when the location server transmits the PRSresource configuration information to both the BS and the UE, the BS maynot transmit the PRS resource configuration information to the UE.However, if the location server transmits the PRS resource configurationinformation only to the BS, the BS may transmit the PRS resourceconfiguration information to the UE. In other words, if step S1805 isomitted, step S1803 may be compulsory. That is, steps S1803 and S1805may be selectively performed. A specific example of the PRS resourceconfiguration information may be based on the later-describedembodiments.

The BS may transmit at least one of a PRS, an SS/PBCH block, or a CSI-RSto the UE (S1807). The UE may transmit a report related to the at leastone of the PRS, the SS/PBCH block, or the CSI-RS to the BS and/or thelocation server, and the BS may transmit the report related to the atleast one of the PRS, the SS/PBCH block, or the CSI-RS to the locationserver (S1809 to S1813). If the UE transmits the report to the locationserver, step S1811 may not be performed. That is, the BS may not forwardthe report to the location server. However, if the UE transmits thereport only to the BS, the BS may forward the report to the locationserver. In other words, if step S1813 is omitted, step S1813 may becompulsory. That is, steps S1811 and S1813 may be selectively performed.Specific information included in the report and a method of transmittingthe report may be based on the later-described embodiments.

The following embodiments may be implemented individually or incombination. In other words, one or more of the embodiments may beimplemented in combination.

Unless otherwise specified, an entity responsible for“configuration/indication” may be a BS, a BS or location serverperforming a positioning operation, or a similar physical/logical node.An entity receiving the configuration/indication is a UE. In thefollowing description, all of a terminal, a user, and a mobile station(MS) may mean a UE.

To configure a specific PRS for a UE, for example, by a PRSconfiguration parameter “PRS-Info” in 3GPP TS36.355, a PRS unit/resourceand/or a PRS resource group/set may be defined as a PRS configurationunit. For example, a PRS configuration may include a configuration of aPRS resource ID, an occupied bandwidth, a periodicity, and the number ofconsecutive slots carrying a PRS, for each PRS resource. Further, one ormore PRSs (e.g., PRS resources or PRS IDs) may be configured as one PRSresource group/set. For example, a plurality of PRS IDs may beconfigured as one PRS group/set.

Further, the UE may determine that PRSs (e.g., PRS resources or PRS IDs)transmitted in a specific PRS resource group/set are from TPs/BSs at thesame location. Alternatively, the location server or the BS mayconfigure/indicate for/to the UE that PRSs (e.g., PRS resources or PRSIDs) transmitted in a specific PRS resource group/set are from TPs/BSsat the same location. When it is said that TPs/BSs are at the samelocation, this may imply that the TPs/BSs are at the same geographiclocation. Further, the TPs/BSs at the same geographical location meanthe same TP/BS.

The location server or the BS may configure/indicate for/to the UE thatdifferent PRSs (e.g., PRS resources or PRS IDs) transmitted in aspecific PRS resource group/set are on the same Tx beam. For example,the BS or the location server may configure/indicate spatialquasi-colocation (QCL) (e.g., QCL type D) between PRSs (e.g., PRSresources or PRS IDs) in a specific PRS resource group/set for/to theUE.

Further, when spatial QCL is configured between PRSs (e.g., PRSresources or PRS IDs) in a specific PRS resource group/set, the UE mayexpect the different PRSs to be transmitted on the same Tx beam from thesame TP/BS. In other words, the UE may expect different PRSs included ina specific PRS resource group/set to be transmitted from the same TP/BS,and expect PRSs configured with spatial QCL (e.g., QCL type D) among thedifferent PRSs to be transmitted on the same Tx beam. That is, one PRSresource or one PRS ID may be associated with one Tx beam, and if thesame spatial QCL is configured between different PRSs corresponding todifferent PRS IDs, the different PRSs may be transmitted on the same Txbeam.

In the following description, a PRS resource may be a unit forconfiguring a PRS and/or PRS configuration parameters including a PRSbandwidth, a PRS configuration ID, PRS muting information, the number ofslots in a PRS occasion, and a PRS occasion group length, like PRSconfiguration parameters “PRS-Info” in TS36.355.

Configuring a PRS at a PRS resource level may be favorable for a narrowbeam-based system such as NR. Because the LTE system is based on a widebeam, one PRS is configured for a reference cell such as a serving cell,and a neighbor cell/TP in the LTE system. That is, “PRS-Info” isconfigured for each of the reference cell and the neighbor cell. Incontrast, a specific TP/BS sweeps multiple beams in a narrow beam-basedmanner in the NR system. Therefore, a TP/BS is highly probable totransmit a PRS on a narrow Tx beam instead of a common beam.Particularly, the TP/BS may have a higher probability of transmitting aPRS on a narrow Tx beam at or above 6 GHs.

From the perspective of a UE which receives a plurality of PRSs ondifferent Tx beams, measurements of the PRSs such as time of arrivals(ToAs), reference signal time differences (RSTDs)/reference signalreceived powers (RSRPs), or signal to nose ratios (SNRs) may bedifferent. Accordingly, the UE needs to distinguish the PRSs transmittedon the different Tx beams from each other.

For this purpose, a different PRS may be transmitted in a different PRSresource by a different Tx beam, so that the UE may be aware that PRSstransmitted in different PRS resources are on different Tx beams. Forexample, although different PRS resources may share time and/orfrequency resources, at least different PRS IDs and/or different PRSsequences may be configured for the different PRS resources in order toenable the UE to distinguish the PRS resources. In other words, PRSresources may include PRS IDs and PRS sequences as well as time and/orfrequency resources. Accordingly, different PRSs may differ in at leastone of PRS time resource, PRS frequency resource, PRS ID, or PRSsequence.

Now, a description will be given of a specific method ofconfiguring/indicating a PRS by a BS and/or a location server, forimproving positioning performance and performing efficient UEpositioning for a low-end UE to which only a narrowband PRS isavailable.

In Embodiment 1 to Embodiment 7 described below, a PRS resource set mayinclude at least one PRS resource. In other words, a PRS resource setmay refer to a group of at least one PRS resource. Further, a PRSresource set may be identical to a PRS block in its meaning.Accordingly, the terms PRS resource set and PRS block areinterchangeably used with each other in the following embodiments.Specifically, a PRS resource set may be a group of a plurality of PRSresources corresponding to one cell/BS/TP. Further, a PRS block may be aplurality of PRS resources corresponding to at least one cell/BS/TP. Inother words, from the perspective of one cell/BS/TP, a PRS block may beidentical to a PRS resource set.

Further, at least one PRS resource set or at least one PRS block mayform a PRS block group. In other words, a PRS block group may refer to agroup of at least one PRS resource set or a group of at least one PRSblock.

Further, the term PRS block group is interchangeable with PRS occasion.That is, a PRS block group and a PRS occasion may be used in the samemeaning in the present disclosure. Further, a PRS resource set may beconfigured on a BS/TP basis. In other words, one PRS resource set may beconfigured for one BS/TP.

Embodiment 1

In the NR system, both a narrowband such as 5 MHz and a wideband aresupported for NR positioning. Therefore, the NR system should be able tosupport various types of UEs and improved positioning performanceirrespective of UE capabilities in order to apply OTDOA. For example,the following three types of UEs may be considered to apply OTDOA in theNR system.

-   -   Type A: a UE of type A may process a wideband PRS without any        limitation.    -   Type B: a UE of type B may have certain hardware limitations,        for example, in a processing capability and/or a battery        lifetime, and may process a wideband PRS.    -   Type C: a UE of type C may have certain hardware limitations,        for example, in a processing capability and/or a battery        lifetime, and may process only a narrowband PRS.

For UEs of type A, it may not be difficult to provide a high positioningaccuracy by lots of RSTD measurements together with a high OTDOA-basedsampling rate. However, UEs such as UEs of type B or type C may need amethod of improving a positioning accuracy, while overcoming hardwarelimitations.

In an OTDOA operation of the NR system, a TP/BS may transmit a widebandPRS and a UE of type C may receive only a limited part of the widebandPRS. Therefore, to improve the positioning accuracy of the UE of type C,a high PRS RE density may be set for an RB in a frequency bandwidthaccessible to the UE of type C, as illustrated in FIG. 19A.

A more accurate positioning performance may be supported for a UE oftype B than for a UE of type C because the UE of type B may additionallyuse a frequency bandwidth to increase the positioning accuracy. However,apart from the UE of type A, support of wideband PRS-based OTDOA for theUE of type B involves hardware limitations, which makes intensiveresearch necessary to provide a high positioning accuracy to the UE oftype B. As one approach, use of both ODTOA-based high and low samplingrates may be considered.

For example, a PRS measurement obtained at a low sampling rate may beused as prior information useful to both a target UE and the BS/locationserver before a high sampling rate-based OTDOA operation, to reducecomputational complexity and enhance RSTD measurement. The low samplingrate and high sampling rate-based OTDOA may be supported in terms of UEimplementation, or may be explicitly indicated by a BS configurationsuch as a narrow bandwidth-based PRS and a wide bandwidth-based PRS toassist with a flexible NR bandwidth configuration such as variousbandwidth parts (BWPs).

For example, when configuring PRSs or PRS resources, the location serverand/or the BS may configure/indicate different PRS RE densitiesaccording to time and/or frequency resources. For example, whenconfiguring a specific PRS or PRS resource for the UE, the BS and/or thelocation server may set a high or low PRS RE density only for a specificbandwidth or specific RBs on the frequency axis. That is, whenconfiguring a PRS and/or a PRS resource, the BS and/or the locationserver may configure/indicate one or more PRS RE densities. Further,BWPs or RBs for which the one or more PRS RE densities are to beconfigured may be configured/indicated by a bitmap or the like.

For example, a high PRS RE density may be set/allocated only for/to afrequency band available to a UE of type C which is capable of usingonly a narrowband PRS to increase the positioning performance of the UEof type C.

Alternatively, when configuring a PRS or a PRS resource for a UE, thelocation server and/or the BS may configure/indicate a different PRSrepetition number according to a PRS frequency bandwidth and/or PRS RBs.That is, the BS and/or the location server may set a different PRSdensity only for a specific bandwidth and/or specific RBs on the timeaxis in a bandwidth carrying the PRS. For example, a larger PRSrepetition number may be set for a PRS corresponding to a “high PRS REdensity region” than for a PRS corresponding to a “low PRS RE density”region, as illustrated in FIG. 19B.

In another example, when one PRS occasion includes four slots, it may beconfigured that the PRS of the “high PRS RE density region” istransmitted in all of the slots, whereas the PRS of the “low PRS REdensity region” is transmitted in a part of the slots.

To perform OTDOA, there is a need for a procedure of matching beamcorrespondence between a target UE and a BS/TP. For this purpose, a beammanagement process of the NR system may be used or an independent beammanagement process may be separately introduced for OTDOA.

This will be described in greater detail. To detect a beam pair forOTDOA-based positioning between a UE and a BS/TP, the BS or the locationserver may configure the UE or indicate to the UE to detect a beam pairhaving a shortest ToA instead of beams having a largest RSRP between theUE and the BS. A ToA may be determined based on the position of a firstpeak of received signals, as illustrated in FIG. 20A. That is, amongsignals A to H received on a plurality of beams, a ToA may be determinedbased on the position of a first peak A, and a beam pair may also bedetermined based on the position of the first peak A.

However, if the RSRP is very small or a noise level is much higher thana signal level at the first peak, it may be difficult to conductreliable communication through a beam pair corresponding to the firstpeak A. Accordingly, when the RSRP of the first peak is equal to or lessthan a specific threshold, a ToA may be determined based on the positionof a second peak B, and a beam pair may also be detected based on thesecond peak B, as illustrated in FIG. 20B. Further, when the UE reportsinformation about the beam related to the ToA to the BS and/or thelocation server, the UE may also report information about a receptionstrength such as the RSRP of the beam.

Specifically, a method of detecting a beam pair by the beam managementprocess of the current NR system will be described. For example, aCSI-RS for L1-RSRP measurement, that is, a CSI-RS for beam managementmay be used. The BS and/or the location server may configure the UE orindicate to the UE to report a CSI-RS resource index corresponding to aminimum ToA and/or the ToA value, for CSI-RS resources included in aspecific CSI-RS resource set with a higher-layer parameter “repetition”set to “on” or “off”. For example, this may be indicated/configuredto/for the UE by a reporting setting.

Specifically, when the BS and/or the location server allocates one ofthree CSI-RS resource sets with repetition set to “off” to each of threeTPs, each CSI-RS resource set may include a plurality of CSI-RSresources. The TPs may transmit the respective CSI-RS resources on Txbeams in different directions. Further, the UE may beindicated/configured to measure a ToA for each CSI-RS resource andselect and report a CSI-RS resource indicator (CRI) with a shortest ToA,for each CSI-RS resource set. Each TP may transmit a PRS, using a Txbeam corresponding to the reported CRI as a reference beam.

Further, the UE may select a reference beam for a PRS beam of a neighborBS/TS by using a CSI-RS for L3-RSRP measurement and/or an SS/PBCH block,and report the selected reference beam to the BS. The UE may measure theToAs of SS/PBCH blocks received from a BS/TP of a neighbor cell, selectthe index of an SS/PBCH block with a shortest ToA, and report theSS/PBCH block index, so that the neighbor cell may use the SS/PBCH blockas a reference beam based on which a PRS Tx beam is determined.

An exemplary independent beam management procedure for OTDOA may begiven as follows. A PRS may be used to match Tx/Rx beam correspondencebetween a neighbor BS/TP and a target UE. The BS and/or the locationserver may configure/indicate some PRS occasions, specific slotscarrying a PRS, or some period of a PRS transmission for the purpose ofTx/Rx beam detection for/to the UE. The PRS used for Tx/Rx beamdetection may be configured/indicated separately from a PRSconfigured/indicated for RSTD measurement, and may have a lower PRS REdensity on the time and/or frequency axis than the PRS for RSTDmeasurement.

For example, as illustrated in FIG. 21, if 10-Tx beam sweeping ispossible for each of 12 TPs/BSs, a PRS resource set/group may beallocated to each TP/BS and 10 PRS resources may be configured/allocatedfor/to each PRS resource set/group. Each TP/BS may transmit the PRSresources corresponding to the TP/BS, while performing Tx beam sweepingduring the duration of 10 symbols.

In other words, each of the 12 TPs/BSs may use one RE in each symbol,and transmit a PRS by a different Tx beam in a different PRS resource ineach symbol, except for the first two symbols corresponding to a controlchannel region.

The UE may be configured/indicated to report a PRS resource index with ashortest ToA in a PRS resource set/group transmitted by each TP/BS tothe BS and/or the location server. For the UE, the PRS RE density may beincreased to 2 or larger for a PRS transmitted after a PRS occasionand/or PRS slots for Tx/Rx beam sweeping, and the UE may recognize thatPRS resources are transmitted on the same Tx beam from a specific TP/BS,except for the PRS occasion and/or PRS slots configured/indicated forTx/Rx beam sweeping, and form an Rx beam suitable for paring with thesame Tx beam. Alternatively, the UE may be configured/indicated to forman Rx beam suitable for reception of a specific PRS resource by the BSand/or the location server.

Further, an RE pattern for PRS transmission may bedesigned/defined/configured for each TP/BS or each specific TP group/BSgroup in association of a symbol carrying a PDCCH to mitigateinterference caused by use of the same time-frequency resources for PRSstransmitted by the TPs/BSs. For example, when a total of 12 TPs/BSs aredivided into two groups each including 6 TPs/BSs, the first two symbolsmay be configured for PDCCH transmission from the first group, and thethird and fourth symbols may be configured for PDCCH transmission fromthe second group to always avoid interference between the two groups inthe first four symbols.

Embodiment 2: PRS Resource Configuration and PRS Resource Group/SetConfiguration

PRS resources may be configured/indicated/defined by one or more of thefollowing configuration parameters in combination as configurationparameters for a PRS having an independent PRS ID, such as “PRS-INFO”for the LTE PRS. Compared to the LTE system in which one LTE PRS isconfigured for each TP/BS, a PRS resource may be one resource in a PRSresource set in the NR system. Further, a PRS transmitted from aspecific TP/BS may be configured/indicated for/to the UE in a pluralityof PRS resources and/or a plurality of resource groups/sets. Further, itmay be very important to configure PRS resources by all or a part of thefollowing parameters in such a manner that different TPs/gNBs/BSs havingdifferent Tx beam sweeping numbers/periodicities may effectivelytransmit PRSs without interfering with each other. This will bedescribed in detail in Embodiment 3.

-   -   Parameters for PRS configuration

1) PRS ID/index or PRS resource ID/index

2) PRS transmission time offset

-   -   This may be configured/indicated in units of X(>=0)        slots/symbols. Further, a PRS transmission time offset may be a        PRS transmission time offset between TPs/BSs, that is, a PRS        transmission time difference between the TPs/BSs. For example,        the PRS transmission time offset may be the difference between a        PRS transmission time of a first TP/BS and a PRS transmission        time of a second TP/BS. The first TP/BS may correspond to a        serving cell or a reference cell, and the second TP/BS may        correspond to a neighbour cell other than the serving cell or        the reference cell.

3) Time-domain behaviour related to PRS transmission

-   -   Periodic PRS transmission/semi-persistent PRS        transmission/aperiodic PRS transmission. If periodic PRS        transmission is configured, a transmission periodicity may be        configured at a time or slot level, such as X(>0) ms or Y(>0)        slots.

4) Bandwidth information

-   -   For example, bandwidth information may be indicated as occupied        RB indexes or as a starting RB index and the number of occupied        RBs. If the bandwidth information is indicated as the occupied        RB indexes, the occupied RB indexes may be indicated by a        bitmap. A BWP ID or system bandwidth information may be        indicated together with or separately from the bandwidth        information.

5) Time/frequency RE density

-   -   Density configurations for a plurality of PRS REs included in        one PRS resource may be different according to frequency        resources such as RBs or time resources such as        symbols/slots/blocks (occasions). For example, a PRS RE density        may be configured according to the difference between the RE        densities of a center RB and an edge RB.

6) Occupied symbol(s) information

-   -   This may be represented as the number of OFDM symbols or symbol        indexes.

7) Frequency RE offset for occupied PRS symbols

-   -   For example, a per-symbol frequency carrier RE offset may be        configured for each of OFDM symbols including a specific PRS        resource, and/or one frequency RE offset may be        configured/indicated for total OFDM symbols including one PRS        resource.

8) Quasi Co-Location (QCL) information

-   -   For example, QCL information may be represented as RS and/or RS        set information. For example, the QCL information may be        represented as an RS and/or RS set ID.

9) Rx panel information of UE

-   -   For example, this may be represented as an Rx panel ID.

Even though different PRS resources share the same time-frequencyresources, different PRS resource IDs or PRS scrambling IDs may beconfigured/indicated for the PRS resources. For example, different PRSresource IDs may be allocated to PRS resources sharing the sametime-frequency resources, so that the PRS resources use different PRSsequences and thus are distinguished from each other.

As such, configuring a PRS on a PRS resource basis may be favorable fora narrow beam-based system such as the NR system. Because the LTE systemis based on a wide beam, only one PRS is configured for a reference cellsuch as a serving cell, and a neighbor cell/TP in the LTE system. Thatis, “PRS-Info” is configured for each of the reference cell and theneighbor cell.

In contrast, a specific TP/BS sweeps multiple beams in a narrowbeam-based manner in the NR system. Therefore, a TP/BS is highlyprobable to transmit a PRS on a narrow Tx beam instead of a common beam.Particularly, the TP/BS may have a higher probability of transmitting aPRS on a narrow Tx beam at or above 6 GHs. Because PRSs transmitted ondifferent Tx beams may have different measurements such asToAs/RSTDs/RSRPs/SNRs, the UE needs to distinguish the PRSs transmittedon the Tx beams from each other. Therefore, a different PRS may betransmitted in a different PRS resource by a different Tx beam, so thatthe UE may be aware that PRSs transmitted in different PRS resources areon different Tx beams. Although different PRS resources may share timeand/or frequency resources, at least different PRS IDs and/or differentPRS sequences may be configured for the different PRS resources in orderto enable the UE to distinguish the PRS resources.

In other words, when it is said that PRS resources are different, thismay mean that PRS IDs and/or PRS sequences as well as time and/orfrequency resources for PRS transmission are different in the presentdisclosure. Accordingly, different PRSs may differ in at least one ofPRS time resource, PRS frequency resource, PRS ID, or PRS sequence.

Further, one or more PRS resources may be configured/indicated as onePRS resource group/set. Further, it may be configured/indicated for/tothe UE that PRS resources included in a specific PRS resource group/setare transmitted from the same TP/BS.

Accordingly, PRS resources and/or PRS resource sets may be configuredsuch that Tx beams and/or TPs/BSs may be distinguished from each otherby PRS resources and/or PRS resource sets in a wireless communicationsystem performing Tx beam sweeping in which a plurality of Tx beams areswitched over time.

For example, PRS resource set/group IDs may not be separatelyconfigured/indicated. Rather, the PRS resource set/group IDs may bereplaced with cell/TP/BS IDs. For example, when a PRS is configured, PRSresources may be configured in conjunction with the ID of a specificneighbor cell/TP/BS, so that a plurality of PRS resources linked to aspecific cell/TP/BS ID may be considered/recognized/configured as onePRS resource group/set. That is, a cell/TP/BS ID may beconsidered/recognized/configured as a PRS resource set/group ID.Alternatively, one PRS resource set/group may be configured/indicatedfor/to the UE in conjunction with specific TP/cell/gNB information.

The following embodiments are implementation examples of a method ofconfiguring PRS resources.

(1) Embodiment 2-1

The BS and/or the location server may configure/indicate time/frequencyresources (e.g., time/frequency REs) used/occupied by one PRS resourcefor/to the UE such that a PRS is configured/transmitted using everysubcarrier RE at least once in an RB configured with/carrying a specificPRS resource. For this purpose, per-symbol frequency RE offsets may beconfigured/indicated for all symbols configured with the specific PRSresource.

PRS resources may be mapped to Tx beams used for PRS transmission from aspecific TP/BS, in a one-to-one correspondence. Further, the UE may beconfigured/indicated to independently obtain and report the measurementsof PRSs transmitted on different Tx beams, such as ToAs, RSTDs, or AOAs,on a Tx beam basis.

Further, in the case where a first peak is detected by cross-correlatingPRS signals to measure a ToA, an RSTD, or the like, the first peak maybe detected more accurately and more easily when the PRSs aretransmitted in all subcarriers than when the PRSs are not transmitted ina specific subcarrier. Accordingly, considering that a specific PRSresource may be transmitted in a plurality of symbols, use of allsubcarriers for PRS resource mapping may be favourable in terms of PRSmeasurement.

(2) Embodiment 2-2

Rx panel information for the UE may be configured/indicated for/to theUE by a PRS reporting configuration for PRS measurement. For example, aPRS reporting configuration for a specific PRS resource and/or PRSresource set may configure/indicate reporting of measurement informationfor a specific Rx panel. For example, the PRS reporting configurationmay configure/indicate reporting of a reporting setting of a CSIframework.

The reception hearability of a PRS signal transmitted by each TP/BS maybe different greatly depending on the Rx panel directionality of the UE.Therefore, because a measurement such as ToA, RSTD, and AoA may bedifferent depending on the Rx panel direction of the UE, if the BS hasat least rough knowledge of the Rx panel direction of the UE, the BS mayindicate to the UE to receive a PRS at a specific Rx panel, which may befavourable in terms of complexity, time delay for PRS transmission andreception, and/or performance.

(3) Embodiment 2-3

When Rx panel information is not configured/indicated separately for/toa UE having a plurality of Rx panels, the UE may report a valueindicated by the BS, selectively by a reporting quantity such as a ToA,an RSTD, and/or an AoA. And/or in the case of ToA or RSTD reporting, theUE may report the smallest of ToA and/or RSTD measurements of theplurality of panels. For example, even though the BS or the locationserver does not transmit a configuration/indication related tomeasurement reporting to the UE, the UE may assign a high priority tothe smallest ToA and/or the smallest RSTD and report the smallest ToAand/or the smallest RSTD.

(4) Embodiment 2-4

Despite the absence of a separate configuration/indication, the UE mayconsider/assume the same Tx beam during the duration of OFDM symbols inwhich a specific PRS resource is configured. Alternatively, the BS mayimplicitly/explicitly configure the UE or indicate to the UE toconsider/assume the same Tx beam during the duration of OFDM symbols inwhich a specific PRS resource is configured.

The above-described Embodiment 2 may be summarized as follows.

1) PRS block (or PRS occasion) configuration

-   -   When one Tx beams is included in one PRS block, one or more PRS        resources may be configured for each TP/BS. When a plurality of        PRS resources are configured, an Rx beam sweeping operation may        be explicitly configured/indicated for/to the UE.

2) In the case where one PRS block corresponds to one or more Tx beams,if a single Tx panel is used, the number of Tx beams for each TP/BS in aPRS block may be equal or different, like a plurality of Tx beams inTDM. Each Tx beam may correspond to one or more PRS resources.

On the contrary, when multiple Tx panels are used as in the case ofconfiguring a plurality of Tx beams in the same time/frequencyresources, different PRS resources may share all or a part oftime/frequency REs and may be spatially distinguished from each other.The different PRS resources may use the same or different PRS sequences.

Similarly to the LTE system, a PRS may be transmitted/configured in agroup of a plurality of symbols/slots or a group of specific blocks inthe NR system. However, it is important to design/configure a PRStransmission unit in consideration of beam sweeping at atransmission/reception end in the NR system. Further, the PRStransmission unit may be configured in the form of repetitions of thesame PRS block or repetitions of different PRS blocks.

Now, a description will be given of specific implementation examples ofa method of allocating PRS resources including a PRS blockconfiguration, a method of configuring a PRS Tx/Rx beam, and a PRSmeasurement method as mentioned in Embodiment 1 and Embodiment 2, withreference to Embodiment 3 to Embodiment 7.

Embodiment 3: PRS Block Configuration

A PRS block may be configured/defined by the following elements. The BSor the location server may configure/indicate a PRS block for/to the UEby one or more of the following pieces of PRS block information.

1) Information about consecutive or distributed OFDM symbols carrying aPRS

-   -   For example, the information may include the indexes of symbols        or the number of symbols, occupied for PRS transmission.

2) Physical cell/BS/TP ID(s) and/or the number of cells/BSs/TPs thattransmit PRSs in the consecutive OFDM symbols

3) PRS resource information and PRS resource group/set information

-   -   For example, the information may include a PRS resource ID        and/or a PRS resource set ID, time/frequency resource        information for PRS transmission, or time/frequency RE mapping        information. Further, a PRS resource set may be configured on a        BS/TP basis. In other words, one PRS resource set may be        configured for one BS/TP.

4) Explicit or implicit information about a specific Tx beam used in acorresponding physical cell/BS/TP

-   -   For example, the information may include one or more PRS        resource IDs and a plurality of PRS resource IDs related to        spatial QCL information.

5) information about a PRS RE density on the time/frequency axis foreach cell/BS/TP and/or each PRS resource

6) Information about a TX/RX panel of the UE or the BS and/or Tx/Rx beaminformation such as a Tx/Rx panel ID of the UE

:

For example, the UE may be indicated/configured to perform a measurementand/or reporting operation only with a specific Rx panel of the UE, fora PRS transmitted in a specific PRS block.

7) Tx/Rx beam information about the UE or the BS

-   -   The Tx/Rx beam information may include spatial QCL reference        information configured for a PRS resource and/or a PRS resource        group/set.

8) Frequency reuse factor, K

-   -   This is information about the number of different TPs/BSs/cells        transmitting PRS REs in the same OFDM symbol in one PRS block.        In the LTE system, six TPs/cells may transmit PRSs at the same        time. In this case, the frequency reuse factor is 6, and the        frequency RE density of the PRSs is 2.

The frequency reuse factor may be the number of PRS resourcestransmitted simultaneously in a specific OFDM symbol of one PRS block,and the frequency RE density of the PRS resources may bedetermined/configured/indicated as 12/K.

9) Repetition factor

-   -   Repeated transmissions of the same PRS RE pattern and/or        specific PRS resources may be configured/indicated. When an Rx        SNR/RSRP improvement operation based on Rx beam sweeping of the        UE and/or coherent Rx combining of the UE at a PRS block group        level is considered/configured/indicated, the repetition factor        may be used as a configuration parameter for a PRS block group.        Coherent Rx combining may refer to reception of a signal (e.g.,        a PRS) a plurality of times by the same Rx beam to improve an        SNR/RSRP.

10) The number of Rx beam sweepings at the UE

-   -   The repetition number of one PRS block or one PRS sub-block may        be determined according to the number of Rx beam sweepings of a        target UE. That is, an Rx beam sweeping factor of the UE may be        configured instead of the repetition factor. However, even        though the number of Rx beam sweepings at the UE is N, a        specific PRS block or PRS sub-block may be transmitted        repeatedly in consideration of the distance between the specific        target UE and a TP. Accordingly, the Rx beam sweeping factor and        the repetition factor of the UE may be configured independently.

In the present disclosure, a PRS block in which the same PRS resource isnot transmitted repeatedly is referred to as a PRS sub-block. That is, aPRS sub-block may be considered to be a special case of a PRS block.Further, a PRS occasion may be constructed/configured/indicated in theform of repetitions of a PRS block, for Rx beam sweeping of the UE orfor increasing an Rx SNR/RSRP for a PRS transmission in the presentdisclosure.

However, when one PRS block is designed to be repetitions of a specificPRS RE pattern in consideration of both Tx and Rx beam sweepingoperations, one PRS block may be defined/interpreted as one PRSoccasion. However, when a PRS occasion is associated with a specificTx/Rx beam, the PRS occasion may be defined/determined as repetitions ofa plurality of PRS blocks in the NR system.

Further, different PRS blocks may share all or a part of time/frequencyresources, and may be transmitted on different Tx beams at the sametime. Further, the PRS blocks may be transmitted in different frequencyresources in the same OFDM symbols. Further, the PRS block/PRSsub-block/PRS occasion may be indicated/configured to/for the UE by theBS and/or the location server.

(1) Embodiment 3-1

A PRS occasion or a PRS block may be defined/configured by usinginformation related to consecutive OFDM symbols in which PRS REstransmitted from one or more TPs/BSs are configured and/or informationrelated to a TP/cell and or PRS resources that transmit a PRS inconsecutive OFDM symbols. Further, information about the PRS block maybe configured/indicated for/to the UE by the BS or the location server.Further, a PRS transmitted from a specific TP/BS during the duration ofone PRS block may be configured to use all frequency REs of an RBconfigured with the PRS at least once. In other words, the PRS block maybe constructed/configured such that there is no unused subcarrier RE(subcarrier tone) in the PRS block. A PRS block may beconfigured/defined with explicit/implicit linkage to Tx beam informationfor PRS transmission from a TP/BS in the PRS block. The PRS block may beconstructed/configured/indicated as follows based on the information.

1) PRS block configured with a single Tx beam of each TP/gNB (or TP/BS)

The BS or the location server may associate a PRS transmitted in one PRSblock from a specific TP/BS only with the same one Tx beam. In thiscase, one PRS block may be a group of one or more OFDM symbols in whichone or more TPs/BSs transmit PRSs on the same Tx beam. The PRStransmitted over the one or more OFDM symbols may beconfigured/constructed such that every subcarrier RE of a PRS RB is usedat least once.

One-to-one mapping between Tx beams and PRS resources may be configured.The total number of PRS resources may be configured/defined for eachTP/BS in correspondence with the number of available/required Tx beamsweepings of the TP/BS.

Alternatively, one-to-many mapping between Tx beams and PRS resourcesmay be configured. However, because a specific TP/BS is allowed to useonly one Tx beam in a PRS block, the UE may be aware that a plurality ofPRS resources are associated with the same Tx beam without a separateindication/configuration. The plurality of PRS resources may be includedin a specific PRS resource set/group.

When a specific TP/BS transmits a plurality of PRS resources or a PRSresource group/set in one PRS block, the same spatial QCL may beconfigured/indicated for the PRS resources or the PRS resourcegroup/set. Further, as one-to-many mapping between Tx beams and PRSresources may be configured, the UE may be configured/indicated tomeasure and/or report a ToA, an RSTD, or the like for each Rx beam,while changing Rx beams. Further, a PRS resource set may be configuredon a BS/TP basis. In other words, one PRS resource set may be configuredfor one BS/TP.

2) PRS block configured with multiple Tx beams of each TP/gNB (or TP/BS)

A PRS block may be designed/constructed/defined/configured inconsideration of a Tx beam sweeping operation in which a TP/BS changes aTx beam over time during PRS transmission. For example, a PRS block maybe configured in consideration of the Tx beam sweeping periodicities ofall TPs/BSs transmitting PRSs in the same PRS block. A configuration orindication of the number of OFDM symbols included in the PRS blockand/or the time/frequency RE density of the PRS block may be differentdepending on whether each of the TPs/BSs transmitting PRSs in the samePRS block has the same number of or a different number of Tx beams. Forexample, a PRS block may be configured such that one PRS resource isassociated with one Tx beam or one Tx beam is associated with aplurality of PRS resources.

Tx beams may be mapped to PRS resources in a one-to-one correspondence.The total number of PRS resources may be configured/defined for eachTP/BS in correspondence with the number of available/required Tx beamsweepings of the TP/BS.

Alternatively, one-to-many mapping between Tx beams and PRS resourcesmay be configured. When a specific TP/BS transmits one or more PRSresources or one or more PRS resource groups/sets in one PRS block, thesame spatial QCL may be configured/indicated for the PRS resources orthe PRS resource groups/sets.

Further, as one-to-many mapping between Tx beams and PRS resources isconfigured, the UE may be configured/indicated to measure and/or reporta ToA, an RSTD, or the like for each Rx beam, while changing Rx beams.For this purpose, it may be indicated to the UE that PRS resources or aPRS resource group/set is transmitted on the same Tx beam by a separateparameter. For example, when a CSI-RS resource set is configured, aseparate configuration parameter such as a higher-layer parameter“repetition” (on/off) used to enable the UE to assume that TPs/BSs usethe same Tx beam may also be used in a PRS resource configuration and/ora PRS resource set configuration.

The time and/or frequency RE density of a PRS block or PRS resources maybe configured or indicated by the BS or the location server. The timeand/or frequency RE density of a PRS block or PRS resources may serve asa basis for configuring or indicating a PRS block and/or PRS resourcesin consideration of a beam sweeping range required for a specific TP/BSand/or the distances between target UEs and the specific TP/BS.Particularly, it may be important to configure a PRS block and/or PRSresources based on the time and/or frequency RE density of the PRS blockand/or the PRS resources to support effective UE positioning in a narrowbeam-based 5G system.

A specific implementation example of a PRS block configuration methodwill be described based on the above description. It is assumed that aPRS may be a UE group-specific signal in the following implementationexamples.

Referring to FIG. 22A, a target UE is located in a specific celloutlined in bold, and all neighbour cells transmit PRSs to the targetUE.

With BS1 and BS2 focused on in the following description, BS1 and BS2transmit PRSs to the specific cell in which the target UE is located. Asillustrated in FIG. 22A, wide beam sweeping ranges may not be requiredin this case. Therefore, each of BS1 and BS2 may only have to transmitthe PRS on one beam without beam sweeping.

Further, because BS1 and BS2 are similar in the distances to the targetUE and the beam sweeping ranges, a BS or location server responsible forpositioning may configure/define PRSs from BS1 and BS2 in one PRS blockfor the UE. For example, a PRS block with a frequency PRS RE density of6 may be configured, as illustrated in FIG. 22B.

Specifically, referring to ‘PRS block (c)’ of FIG. 22B, a differentfrequency offset may be configured in each symbol, for each TP/BS, sothat the TP/BS may use all subcarrier REs across two OFDM symbols.Further, a first peak may be measured more accurately throughcross-correlation in ‘PRS block (c)’ of FIG. 22B than in ‘PRS block (b)’of FIG. 22B. Therefore, it may be appropriate to configure a per-symbolfrequency RE offset for all OFDM symbols in which a PRS block and/or PRSresources are included.

(2) Embodiment 3-2

A PRS block may be configured or indicated only with TPs/BSs having thesame number of Tx beam sweepings for PRS transmission. For example, itmay be configured or indicated that only PRS resource groups/setsincluding the same number of PRS resources among different PRS resourcegroups/sets are included in one PRS block. Further, a PRS resource setmay be configured on a BS/TP basis. In other words, one PRS resource setmay be configured for one BS/TP.

Additionally, a PRS block may be configured only when time/frequencyresources (e.g., time/frequency REs) occupied by one PRS resource areallocated such that every subcarrier RE included in an RB carrying aspecific PRS resource is used at least once.

For example, referring to FIG. 23A, BS3, BS4 and BS5 transmit PRSs. BS3,BS4 and BS5 have wider beam sweeping ranges than BS1 and BS2. Therefore,when each of BS3, BS4 and BS5 transmits a PRS on one Tx beam, a coverageproblem may occur. Accordingly, BS3, BS4 and BS5 may need a multiple Txbeam sweeping operation. As illustrated in FIG. 23B, if each BStransmits a PRS by two Tx beam sweepings, uses three OFDM symbols per Txbeam, and sets a PRS RE density of 4 on the frequency axis, with PRS REsarranged equi-distantly, a PRS block including six OFDM symbols may beconfigured.

In this case, a different PRS RE offset on the frequency axis may beconfigured for each symbol, from the perspective of each BS/TP, so thatall subcarrier REs may be occupied during the duration of the threesymbols. For example, if the PRS subcarrier RE offsets of the threesymbols are set to 0, 1, and 2 for BS5, PRS resources may be configuredas illustrated in FIG. 23B. Further, different PRS resource IDs ordifferent PRS scrambling IDs may be assigned to PRSs associated with Txbeam #1 and Tx beam #2 to distinguish the different beams from eachother, although the PRSs share time/frequency resources. Further, the BSor the location server may configure or indicate different PRS resourcesfor or to the UE such that the time/frequency resources of the PRSresources are completely independent of each other.

In other words, the UE may measure or estimate a ToA bycross-correlating a PRS received on Tx beam #1 with a PRS received on Txbeam #2.

Further, BS1 and BS2 are farther from the target UE than BS3, BS4 andBS5 in FIGS. 22A and 23A. Therefore, to increase the reception SNR/RSRP,one PRS block and/or one PRS block group/set may be configured asrepetitions of a PRS block structure such as ‘PRS block (c)’ in FIG.22B.

(3) Embodiment 3-3

Referring to FIG. 24, when a PRS is configured, it may be configured orindicated that a specific PRS RE pattern or a specific PRS resource isrepeated in one PRS block group (or PRS occasion). For example, a“repetition parameter” which is an independent parameter forconfiguring/indicating PRS block and/or PRS block group may be used anda PRS transmission pattern such as one PRS block may be configured toequally repeated to N times through a separate independent configurationparameter (e.g., “repetition factor”). Particularly, when a PRS blockgroup is configured, N-times repetitions of a PRS block in the PRS blockgroup may be configured or indicated by an explicit configurationparameter (e.g., repetition factor) indicating N-time repetitions of thesame PRS. The PRS block may include at least one PRS resource. Forexample, the PRS block may include PRS resource sets for at least oneBS/TP/cell.

Accordingly, a PRS block may be identical to a PRS resource set in itsmeaning from the viewpoint of one cell/BS/TP. Repetitions of at leastone PRS resource in a PRS block may be configured for the BS and/or theUE by the location server or for the UE by the BS. That is, the timeduration of the PRS block group in which at least one PRS resourceincluded in one PRS is repeated may be equal to or larger than theproduct between at least one PRS resource duration and the repetitionfactor ‘N’. A PRS block group and a PRS occasion may be used in the samemeaning. In other words, a PRS occasion may have a duration equal to thetransmission periodicity of a PRS resource set/PRS block, and at leastone PRS resource included in a PRS resource set/PRS block may berepeated ‘N’ times during the duration of the PRS occasion. That is, atleast one PRS resource is allocated ‘N’ times within the total timeduration of a PRS occasion/PRS block group, with no PRS resource in theremaining period except for the ‘N’ repetitions of the PRS resource.Further, a PRS resource set may be configured on a BS/TP basis. In otherwords, one PRS resource set may be configured for one BS/TP.

When a PRS block and/or a PRS block group is periodically transmitted, arepetition number of a PRS transmission pattern such as a PRS block maybe configured for a PRS block and/or a PRS block group transmitted in aspecific period. Further, the UE may be configured or indicated tomeasure the ToAs, RSTDs, and/or AoAs of PRS resources of N-time repeatedPRS blocks, while changing an Rx beam N times, and/or report themeasurements.

Embodiment 3-3 may be favourable in supporting a positioning operationin the narrow beam-based NR system. For example, because BS1/BS2 isfarther from the target UE than BS3/BS4/BS5 in FIGS. 25A and 25B,BS1/BS2 needs to transmit a PRS repeatedly and hence improve thereception SNR or hearability performance of the PRS.

For this purpose, although beam sweepings in BS3, BS4 and BS5 outnumberbeam sweepings in BS1 and BS2, BS1 and BS2 may repeat PRSs three timesto improve reception SNRs/hearability, as illustrated in FIG. 25B.Referring to FIG. 25B, a PRS block (i.e., PRS RE pattern) associatedwith BS2 may be transmitted repeatedly. As PRS resource #1 from BS2 isconfigured to span six OFDM symbols, BS2 may transmit a PRS over sixsymbols like a PRS block including PRSs from BS3, BS4, and BS5.

With reference to FIGS. 24 to 25B, a specific example of repeating PRSresources in a PRS occasion in FIG. 24 will be described. Referring toFIG. 25A, PRS resource #1 and PRS resource #2 may be allocated adjacentto each other in one PRS resource set. A group of these adjacent PRSresource #1 and PRS resource #2 may be transmitted as many times as arepetition factor ‘N’, as illustrated in FIG. 24. As illustrated in FIG.25B, PRS resource #1 included in a PRS resource set may be transmittedrepeatedly as many times as a repetition factor ‘N’ in a PRS occasion.

One PRS resource may be associated with one Tx beam. For example, PRSresource #1 may be associated with Tx beam #1, and PRS resource #2 maybe associated with Tx beam #2. Therefore, for example, if four Tx beamsare available, PRS resource #1 to PRS resource #4 may be used, and agroup of PRS resource #1 to PRS resource #4 which have been allocatedadjacent to each other may be transmitted repeatedly as many times as arepetition factor ‘N’.

(4) Embodiment 3-4

The frequency RE density of PRSs or PRS resources in a PRS block may beconfigured dependently on an RE/symbol/RB basis. Further, the BS or thelocation server may configure or indicate the frequency RE density ofthe PRSs or PRS resources in the PRS block for or to the UE according tothe number of TPs/BSs transmitting PRSs simultaneously in one OFDMsymbol. For example, if the number of TPs/BSs transmitting PRSs in thesame symbol is M, the frequency PRS RE density may be configured orindicated as 12/M REs (or symbols or RBs).

Alternatively, the BS or the location server may configure or indicatethe frequency RE density of PRSs or PRS resources in a PRS block on anRE/symbol/RB basis for or to the UE according to the number of PRSresources transmitted simultaneously in one OFDM symbol. For example, ifthe number of PRS resources transmitted in the same symbol is M, thefrequency PRS RE density may be configured or indicated as 12/M REs (orsymbols or RBs).

In this case, a TP/BS farther from a target UE may require a smallerbeam sweeping range than a TP/BS nearer to the target UE. However, theTP/BS farther from the target UE needs to have an increased repetitionnumber to secure the SNR/RSRP of a PRS received at the target UE.Accordingly, when a PRS block is configured for a PRS transmitted from aTP/BS requiring a large number of Tx beam sweepings, a high PRS REdensity may be configured for the TP/BS. In contrast, when a PRS blockis configured for a PRS transmitted from a TP/BS requiring a smallnumber of Tx beam sweepings, a low PRS RE density may be configured forthe TP/BS. A PRS transmitted from a TP/BS may be PRS resources and/or aPRS resource set. Further, a PRS resource set may be configured on aBS/TP basis. In other words, one PRS resource set may be configured forone BS/TP.

(5) Embodiment 3-5

A different time PRS RE density and/or a different frequency PRS REdensity may be configured or indicated for each PRS resource included ina PRS block. For example, a different frequency PRS RE density and/or adifferent time PRS RE density may be configured or indicated for aper-Tx beam PRS of each of a plurality of TPs/BSs transmitting PRSs inthe same PRS block.

Further, the frequency RE densities of PRS resources in one PRS blockmay be configured or indicated in association with or in conjunctionwith the numbers of Tx beam sweepings that change over time while thePRSs are being transmitted in the PRS block. Further, the number of OFDMsymbols and/or an OFDM symbol duration in a PRS block, in which each PRSresource is included, may be configured or indicated in association withthe frequency RE density and the number of Tx beam sweepings of the PRSresource.

For example, as described above, an OFDM symbol duration spanned by aPRS block and/or PRS resources may be configured as a minimum requiredOFDM symbol to satisfy the condition that “every subcarrier RE in an RBconfigured with a specific PRS resource is used at least once for PRStransmission”.

A higher frequency RE density may be configured or indicated for a PRSresource transmitted in one PRS block from a TP/gNB/BS with a largernumber of Tx beam sweepings than a PRS resource transmitted in the PRSblock from a TP/gNB/BS with a smaller number of Tx beam sweepings. Forexample, if a large number of PRS resources are related to a specificTP/gNB/BS among the PRS resources of one PRS block, a relatively highfrequency RE density may be configured for the PRS resources. In otherwords, considering that one PRS resource group/set is associated with asingle TP/gNB/BS, and PRS resources included in the PRS resourcegroup/set correspond to a Tx beam of the TP/gNB/BS, if a specific PRSgroup/set includes more PRS resources than another PRS group/set, arelatively high frequency RE density may be configured or indicated forthe PRS resources included in the specific PRS resource group/set.

For example, regarding a plurality of TPs/gNBs/BSs that transmit PRSs ina specific PRS block, the frequency RE density of PRS resourcestransmitted from each TP/gNB/BS may be configured or indicated ininverse proportion to the number of Tx beam sweepings which is changedover time for PRS transmission in the TP/gNB/BS. For example, when twoBSs perform M Tx beam sweepings and N Tx beam sweepings respectively forPRS transmission in the same PRS block, the frequency RE densities ofPRS resources transmitted from the BSs may be configured or indicatedsuch that the ratio between the frequency RE densities is N:M.

Referring to the left drawing of FIG. 26A, TPs/gNBs/BSs performdifferent numbers of Tx beam sweepings, for PRS transmission in one PRSblock. The PRS block is so configured that the number of Tx beamsweepings is 4 for TP/BS #1, 2 for TP/BS #2, and 2 for TP/BS #3.

The right drawing of FIG. 26A and FIG. 26B illustrate time/frequencyresources occupied by PRS resources of each TP/BS. Referring to FIGS.26A and 26B, the frequency RE density of four PRS resources transmittedfrom TP/BS #1 is 6, and the frequency RE density of two PRS resourcesfrom each of TP/BS #2 and TP/BS #3 is 3. That is, since TP/BS #1 hastwice the number of Tx beam sweepings of TP/BS #2 and TP/BS #3, thefrequency RE density may be set to be twice smaller for TP/BS #1 thanfor TP/BS #2 and TP/BS #3 in FIGS. 26A and 26B.

(6) Embodiment 3-6

The BS or the location server may bundle one or more PRS blocks andconfigure/define/indicate the bundle as one PRS block group/set.

The PRS block group may be configured or indicated for repeatedtransmissions of a plurality of PRS blocks. Further, a repetition numbermay be configured or indicated for each individual PRS block, forrepeated transmissions of the PRS block in the PRS block group. Forexample, a specific PRS block may be repeated in one PRS block group,and this repetition may be configured in conjunction with Rx beamsweeping of the UE. When the UE receives a PRS while changing an Rx beamin each PRS block, the UE may receive PRS blocks of the same pattern andmeasure RSTDs, TOAs, or AoAs of each PRS resource in the PRS blocks.Alternatively, it may be configured that a specific PRS block isrepeated in order to increase the reception SNR of the PRS block inconsideration of the distance between a BS and a target UE.

As described above, repeated transmissions of a PRS block may improvethe PRS reception SNR/RSRP performance of the UE, and enable the UE toreceive PRSs included in one PRS block by different Rx beams and acquirea measurement such as an RSTD, a ToA, and/or an AoA for each Rx beam ofthe UE.

A PRS block repeated in a PRS block group/set may be discontinuous intime. Obviously, the PRS block may be continuously repeated. Forexample, even though a specific PRS block is repeatedly transmitted inconsecutive slots, the PRS block may be repeated distributedly in thepresence of a region carrying a PDCCH and/or a UL region in the PRSblock group/set according to a slot format.

Further, one or more different PRS block indexes or different PRS blockIDs may be included as a PRS block group configuration parameter.

Further, a PRS may be periodically transmitted, with a PRS blockgroup/set used as one transmission unit. For example, when PRS blockgroups are configured, a transmission periodicity for PRS transmissionmay be configured or indicated for each PRS block group/set. Thetransmission periodicity may be different for each PRS block group, andwhen the PRS block group/set is configured, time offset information fora periodicity may be configured or indicated in order to preventcollision between PRS block groups. For example, a time offset may beconfigured or indicated as an OFDM symbol offset, a slot offset, or thelike.

Further, a specific PRS block group may be configured or indicated inassociation with a specific Rx panel and/or Rx beam of the UE. Forexample, a different PRS block group may be configured or indicated foreach Rx panel of the UE. The PRS block group/set may include a pluralityof different PRS blocks, and the number of times each PRS block isrepeated in the PRS block group/set may be configured or indicated.Different BSs/TPs/gNBs may transmit PRSs in different PRS blocks. If thesame BS/TP/gNB transmits a PRS in different PRS blocks, a different PRSTx beam may be used for each PRS block. For example, different PRSresources included in the same PRS resource group/set may be associatedwith different PRS Tx beams.

4. Embodiment 4: PRS Tx Beam Configuration

In the narrow beam-based NR system, information about a Tx beam on whicha PRS is transmitted may be required to support effective UEpositioning. For example, it is assumed that target UEs are divided intotwo groups as illustrated in FIG. 27A, rather than UEpositioning/location estimation is performed for all UEs of acell/region. When BS1 and BS2 transmit PRSs to target UE group #1 andtarget UE group #2 in FIG. 27A, it may be effective for BS1 and BS2 totransmit the PRSs only in consideration of necessary Tx beams. In otherwords, as illustrated in FIG. 27A, a PRS may be transmitted to target UEgroup #1 on two Tx beams and to target UE group #2 on one Tx beam, basedon a required Tx beam sweeping range.

Therefore, BS1 does not need to perform Tx beam sweeping in alldirections, and the BS may indicate to the location server or thelocation server may indicate to the BS that only beams marked with soldlines or PRS resource associated with the beams among all available PRSresources are used as illustrated in the right drawing of FIG. 27A.

(1) Embodiment 4-1

The BS/location server may configure or indicate, for or to the locationserver/BS, information about a Tx beam for PRS transmission from aspecific TP/gNB/cell through a protocol such as NRPPa. For example,information about a Tx beam direction for PRS transmission from aspecific TP/BS may be configured or indicated. The information about theTx beam direction may be information about an angle of the Tx beamdirection. For this purpose, the BS/location server may configure orindicate for or to the location server/BS to use only specific PRSresource(s) from among resource set(s) or PRS resource(s) so that onlyone or more specific PRS resources are used among PRS resource sets orPRS resources available to be used by a specific TP/gNB/cell. Forexample, a PRS resource set may be configured on a BS/TP basis. In otherwords, one PRS resource set may be configured for one BS/TP.

For example, each of a plurality of PRS resources included in a specificPRS group may be associated with one of beams transmitted in differentdirections from each TP/BS, and information about this may be known tothe BS and/or the location server. Therefore, as illustrated in FIG.27A, the BS/the location server may configure or indicate for or to thelocation server/the BS that only one or more PRS resources associatedwith one or more specific beam directions are used, so that a PRS may betransmitted only in a necessary direction from a specific TP/gNB/BS by aprotocol such as NRPPa.

Further, in the narrow beam-based wireless system, it may be unnecessaryfor a UE to receive PRSs transmitted in all directions from eachTP/gNB/BS due to too a low reception RSRP/SNR or a problem in ToA/RSTDmeasurement accuracy. Additionally, since reception of PRSs transmittedin all directions may increase latency and overhead, an effective PRSconfiguration and an effective measurement based on a PRS configurationmay be required.

For this purpose, the location server may configure PRS resourcesUE-specifically and/or UE group-specifically based on information abouttarget UEs and/or target UE groups indicated to the location server/BSby the BS/location server and Tx beam information of each TP/gNB/BSassociated with the information about the target UEs and/or the targetUE groups, so that the UE may not consider unnecessary Tx beams of aneighbor cell/TP/BS and/or a serving cell/TP.

For example, referring to FIG. 27B, it is assumed that there are targetUE groups #1, #2, and #3, and BS1 is among BSs that transmit PRSs to thetarget UE groups. Since BS1 is capable of transmitting a PRS to targetUE group #3 by a single Tx beam, only PRS resource #1 out of PRSresources corresponding to the single Tx beam may be configured fortarget UE group #3. On the other hand, PRS resources #1, #2, and #3 maybe configured for target UE group #2, and PRS resources #4, #5, and #6may be configured for target UE group #1.

(2) Embodiment 4-2

The BS, the location server, or a BS responsible for positioning mayconfigure or indicate, for/to the UE, information about a Tx beam and/orTx beam group on which a PRS is transmitted from a reference cell/TP/BSand/or a neighbour cell/TP/BS. The Tx beam and/or Tx beam groupinformation may include information about the angle of each Tx beam. Forexample, the information about the angle may be information about an AoAor angle of departure (AoD). Further, the information about the AoA orAoD may include information about a horizontal angle and informationabout a vertical angle. Further, the information about the AoA or AoDmay be associated with one or more ground control stations (GCSs) orlocation services (LCSs).

A configuration related to a Tx beam carrying a PRS and/or aconfiguration related to a PRS resource may be configured or indicatedUE-specifically and/or UE group-specifically. For example, when the BSor the location server configures information about a referencecell/TP/BS and/or a neighbour cell/TP/BS for the UE, the BS or thelocation server may configure or indicate an SS/PBCH block ID or SS/PBCHblock index for radio resource management (RRM), a CSI-RS ID or CSI-RSindex for RRM, and/or a PRS ID or PRS index along with a specificphysical cell ID. The specific physical cell ID may be the ID of a TP/BSassociated with a specific physical cell.

To receive a PRS from the reference cell/TP/BS and/or the neighbourcell/TP/BS, use of an Rx beam on which an SS/PBCH block, a CSI-RS,and/or a PRS corresponding to the configured or indicated ID or indexmay be configured or indicated. For this purpose, the SS/PBCH block,CSI-RS, and/or PRS corresponding to the configured or indicated ID orindex may be configured or indicated as a spatial QCL reference for PRSresources, so that the UE may be aware of information about thedirection of a Tx beam of the PRS transmitted from the referencecell/TP/BS and/or the neighbour cell/TP/BS.

In other words, to receive a PRS and perform positioning, the UE mayreceive the PRS in an Rx beam corresponding to an RS transmitted fromthe serving cell or the neighbour cell, assuming that the RS isspatially QCLed with the PRS received for positioning. For thispurposed, the UE may receive the ID of the serving cell or neighbourcell transmitting the RS and information related to the index of the RSassumed to be spatially QCLed with the PRS. The RS may be theafore-described SS/PBCH block, CSI-RS, and/or PRS. Therefore, the indexof the RS transmitted together with the ID of the serving cell or theneighbour cell may be the index of the SS/PBCH block, the CSI-RS (e.g.,CRI), or the PRS resource. Further, the ID of the serving cell orneighbour cell may be the ID of a TP/BS corresponding to the servingcell or neighbor cell. Further, the BS or the location server maytransmit, to the UE, both the ID of the serving cell or neighbour celland the ID of the TP/BS corresponding to the serving cell or neighborcell. In other words, the BS or the location server may transmit atleast one of the cell ID or the ID of the TP/BS corresponding to thecell to the UE.

If the RS is a PRS, the PRS may be transmitted to determine the Rx beamof a PRS for positioning. For example, upon receipt of a first PRS, theUE may determine an Rx beam based on the first PRS, and receive a secondPRS for positioning on the determined Rx beam, assuming that the secondPRS is received on the same Rx beam as the determined Rx beam.

Further, spatial QCL between the PRS and the RS may imply that a spatialreception parameter for receiving the RS may be used as a spatialreception parameter for PRS reception, and the use of the same spatialreception parameter may mean the same Rx beam.

When an Rx beam is determined for reception of a PRS for positioning,the Rx beam may be determined through beam sweeping for a plurality ofRSs having the same spatial-domain transmission filter. Further, if theplurality of RSs have different spatial-domain transmission filters, theUE may receive the RSs on a fixed Rx beam and receive the PRS, assumingthat an RS having the largest RSRP on the fixed Rx beam is QCLed withthe PRS for positioning.

Alternatively, referring to FIG. 27B, when a PRS or a PRS resource isconfigured, information related to a Tx beam direction such as a Tx beamangle may be configured or indicated. Alternatively, the Tx beamdirection of the PRS may be predetermined or preconfigured according tothe index of the PRS resource. Based on the Tx beam direction, thelocation server or the BS may configure or indicate a PRS resourceand/or a PRS resource group/set UE-specifically and/or UEgroup-specifically according to a target UE and/or a target UE group.

The PRS resource and/or the PRS resource group/set may be configured orindicated based on the transmission periodicity of a specific PRS block,PRS block group, and/or PRS. Further, AoD information may be indicatedor configured implicitly to or for the UE by a PRS resource index. Forexample, given 12 PRS resources in total, AoD 0 degrees may be set asPRS resource index #1 and AoD 360 degrees may be set as PRS resourceindex #12, for the UE. In other words, when there are a total of 12 PRSresources, AoDs may be indexed as PRS resources at intervals of 30degrees. For example, PRS resource index #2 may be related to AoD 30degrees, and PRS resource index #11 may be related to AoD 330 degrees.That is, a Tx beam direction (e.g., AoD) in which each PRS resource istransmitted may be identified automatically by the UE orconfigured/indicated for/to the UE by the BS and/or the location server,according to the total number of PRS resources included in a specificPRS resource group/set.

Computing cross-correlations of all PRS resources to acquiremeasurements of ToAs, RSTDs, or the like may significantly increasecomputational complexity. If the UE obtains RSTD measurements from PRSstransmitted from a total of M TPs/BSs/cells and receives PRSs on N Txbeams per TP/BS/cell, the UE needs to perform a total of M×Ncross-correlation computations. Particularly in a wideband, if M and Nare equal to or larger than a predetermined value, the UE may havedifficulty in performing cross-correlation computations according to itscapability.

Therefore, to reduce the computational complexity, a PRS resource havinga maximum RSRP/SNR/SINR may be selected, and a ToA may be calculated byperforming a cross-correlation operation only for a PRS received in theselected PRS resource. Further, a statistical error of a ToA/RSTD may bederived from an SNR/SINR, and thus a very accurate association may bedetected. Accordingly, a Tx beam carrying a PRS may be detected based ona Tx signal strength such as an SNR/SINR/RSRP, and a cross-correlationoperation may be performed for the selected Tx beam.

Embodiment 5: RSRP/SNR and ToA/RSTD

It may be indicated or configured that the UE should measure the ToAs ofall PRS resources transmitted from a specific TP/BS/cell and calculatean RSTD based on a PRS resource having a minimum ToA. The PRS resourcestransmitted from the specific TP/BS/cell may be set as a PRS resourcegroup/set. Further, RSRP measurement using a plurality of PRS resourcesor one PRS resource group/set transmitted from a specific TP/BS/cell maybe indicated or configured to or for the UE.

Further, the UE may be configured or indicated to report the index or IDof a PRS resource having a maximum RSRP/SNR/SINR and/or a ToA and/orRSTD value measured based on the PRS resource having the maximumRSRP/SNR/SINR to the BS or the location server. The measurement and/orreporting configuration may be configured or indicated UE-specificallyaccording to a UE performance level for cross-correlation computation.

Considering that multiple beams and multiple panels are available to theBS and the UE, measurements and/or reports of a ToA, an RSTD, and angleinformation such as an AoA/AoD using a PRS by the UE may be classifiedinto the following levels.

-   -   Tx beam specific    -   Tx beam group specific    -   Rx panel specific    -   Rx panel specific    -   Rx beam specific    -   Rx beam group specific

Embodiment 6: Measurement/Reporting Configuration in Consideration ofPlural Rx Panels

The BS or the location server may configure or indicate to the UE tomeasure and report an RSTD, ToA, and/or AoA on an Rx panel basis.

When the UE is indicated or configured, by the BS or the locationserver, to report the ToA and/or RSTD measurements acquired from aplurality of Rx panels on an Rx panel basis, the UE may report thesmallest of the ToA and/or RSTD values to the BS or the location server.The smallest ToA may be assumed to be the most accurate value. Forexample, when the UE is configured or indicated to report one RSTDand/or ToA out of the RSTD, ToA, and/or AoA measurements from theplurality of Rx panels, the UE may report the smallest of the ToA and/orRSTD values measured on an Rx panel basis to the BS or the locationserver.

Further, the BS or the location server may configure or indicate to theUE to measure/report a ToA, RSTD, and/or AoA using a specific Rx panelby indicating the ID of the Rx panel or the index of an Rx beam.

Further, the BS or the location server may configure or indicate to theUE to measure/report the ToAs, RSTDs, and/or AoAs of PRSs transmitted onspecific Tx beams, using a specific Rx panel and/or Rx beam. For thispurpose, when a PRS resource and/or a PRS resource set is configured forthe UE, an Rx panel ID and/or an Rx beam index related to the PRSresource and/or the PRS resource set may be configured or indicated.

Embodiment 7: Rx Beam Sweeping Configuration

Although the UE is capable of generating a plurality of Rx beams, thenumber of Rx beams that the UE may use at the same time may be limitedaccording to the number of Rx panels at the UE. Therefore, to enable theUE to receive a PRS and measure the ToA, RSTD, and/or AoA of the PRS,while performing Rx beam sweeping in multiple directions, an Rx beamsweeping time unit may be configured/indicated by the BS orpreconfigured.

(1) Embodiment 7-1: PRS Block-Level Rx Beam Sweeping

The BS or the location server may configure or indicate to the UE toacquire ToA and/or RSTD measurements, while changing an Rx beam in everyPRS block and/or every PRS block group. When a PRS block is repeated ina specific PRS block group, the UE may automatically identify that thePRS resources of each PRS block are transmitted by the same Tx beam.Because a PRS block is designed by reflecting information about Tx beamsthat each TP/BS sweeps, this UE operation may be appropriate.

The BS or the location server may explicitly configure or indicate thatthe PRS resources of each PRS block are transmitted by the same Tx beam.

(2) Embodiment 7-2: Sub-Time Unit-Level Rx Beam Sweeping

Multiple repeated transmissions of a PRS block may cause excessivelatency. Therefore, reception of a PRS by changing an Rx beam aplurality of times within a single symbol may be considered. In thiscase, when a PRS block is configured, PRS resources included in the PRSblock should satisfy the following conditions.

-   -   Considering subcarrier REs used for all PRS resources included        in one PRS block, it should be configured or indicated that the        subcarrier REs are equi-distantly used in each symbol included        in the PRS block. In other words, the RE patterns of all PRS        resources should be configured or indicated such that the PRS        resources may be transmitted in interleaved frequency division        multiplexing (IFDM) in each symbol included in the PRS block.    -   Time/frequency resources or time/frequency REs for one PRS        resource should be configured such that every subcarrier RE is        used at least once in an RB configured with a specific PRS        resource.

The various descriptions, functions, procedures, proposals, methods,and/or operational flowcharts of the present disclosure described inthis document may be applied to, without being limited to, a variety offields requiring wireless communication/connection (e.g., 5G) betweendevices.

Hereinafter, a description will be given in more detail with referenceto the drawings. In the following drawings/description, the samereference symbols may denote the same or corresponding hardware blocks,software blocks, or functional blocks unless described otherwise.

FIG. 28 illustrates a communication system 1 applied to the presentdisclosure.

Referring to FIG. 28, a communication system 1 applied to the presentdisclosure includes wireless devices, BSs, and a network. Herein, thewireless devices represent devices performing communication using radioaccess technology (RAT) (e.g., 5G new RAT (NR)) or long-term evolution(LTE)) and may be referred to as communication/radio/5G devices. Thewireless devices may include, without being limited to, a robot 100 a,vehicles 100 b-1 and 100 b-2, an extended reality (XR) device 100 c, ahand-held device 100 d, a home appliance 100 e, an Internet of things(IoT) device 100 f, and an artificial intelligence (AI) device/server400. For example, the vehicles may include a vehicle having a wirelesscommunication function, an autonomous driving vehicle, and a vehiclecapable of performing communication between vehicles. Herein, thevehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone).The XR device may include an augmented reality (AR)/virtual reality(VR)/mixed reality (MR) device and may be implemented in the form of ahead-mounted device (HMD), a head-up display (HUD) mounted in a vehicle,a television, a smartphone, a computer, a wearable device, a homeappliance device, a digital signage, a vehicle, a robot, etc. Thehand-held device may include a smartphone, a smartpad, a wearable device(e.g., a smartwatch or a smartglasses), and a computer (e.g., anotebook). The home appliance may include a TV, a refrigerator, and awashing machine. The IoT device may include a sensor and a smartmeter.For example, the BSs and the network may be implemented as wirelessdevices and a specific wireless device 200 a may operate as a BS/networknode with respect to other wireless devices.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g.,NR) network. Although the wireless devices 100 a to 100 f maycommunicate with each other through the BSs 200/network 300, thewireless devices 100 a to 100 f may perform direct communication (e.g.,sidelink communication) with each other without passing through theBSs/network. For example, the vehicles 100 b-1 and 100 b-2 may performdirect communication (e.g. vehicle-to-vehicle(V2V)/vehicle-to-everything (V2X) communication). The IoT device (e.g.,a sensor) may perform direct communication with other IoT devices (e.g.,sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, or 150 c may beestablished between the wireless devices 100 a to 100 f/BS 200, or BS200/BS 200. Herein, the wireless communication/connections may beestablished through various RATs (e.g., 5G NR) such as uplink/downlinkcommunication 150 a, sidelink communication 150 b (or, D2Dcommunication), or inter BS communication (e.g. relay, integrated accessbackhaul (IAB)). The wireless devices and the BSs/the wireless devicesmay transmit/receive radio signals to/from each other through thewireless communication/connections 150 a and 150 b. For example, thewireless communication/connections 150 a and 150 b may transmit/receivesignals through various physical channels. To this end, at least a partof various configuration information configuring processes, varioussignal processing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), and resourceallocating processes, for transmitting/receiving radio signals, may beperformed based on the various proposals of the present disclosure.

FIG. 29 illustrates wireless devices applicable to the presentdisclosure.

Referring to FIG. 29, a first wireless device 100 and a second wirelessdevice 200 may transmit radio signals through a variety of RATs (e.g.,LTE and NR). Herein, {the first wireless device 100 and the secondwireless device 200} may correspond to {the wireless device 100 x andthe BS 200} and/or {the wireless device 100 x and the wireless device100 x} of FIGS. 26A and 26B.

The first wireless device 100 may include one or more processors 102 andone or more memories 104 and additionally further include one or moretransceivers 106 and/or one or more antennas 108. The processor(s) 102may control the memory(s) 104 and/or the transceiver(s) 106 and may beconfigured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 102 may process informationwithin the memory(s) 104 to generate first information/signals and thentransmit radio signals including the first information/signals throughthe transceiver(s) 106. The processor(s) 102 may receive radio signalsincluding second information/signals through the transceiver 106 andthen store information obtained by processing the secondinformation/signals in the memory(s) 104. The memory(s) 104 may beconnected to the processor(s) 102 and may store a variety of informationrelated to operations of the processor(s) 102. For example, thememory(s) 104 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 102or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 102 and the memory(s) 104 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 106 may be connected to the processor(s) 102 andtransmit and/or receive radio signals through one or more antennas 108.Each of the transceiver(s) 106 may include a transmitter and/or areceiver. The transceiver(s) 106 may be interchangeably used with RadioFrequency (RF) unit(s). In the present disclosure, the wireless devicemay represent a communication modem/circuit/chip.

Specifically, commands and/or operations controlled by the processor 102and stored in the memory 104 in the wireless device 100 according to anembodiment of the present disclosure will be described below.

While the operations are described in the context of a control operationof the processor 102 from the perspective of the processor 102, softwarecode for performing these operations may be stored in the memory 104.

The processor 102 may control the transceiver 106 to receive informationrelated to a PRS resource configuration from the second wireless device200 or the location server 90 of FIG. 33. Specific embodiments of theinformation related to the PRS resource configuration are based on theforegoing description.

The processor 102 may control the transceiver 106 to receive at leastone of a PRS, an SS/PBCH block, or a CSI-RS from the second wirelessdevice, and control the transceiver 106 to transmit a report related tothe at least one of the PRS, the SS/PBCH block, or the CSI-RS. Specificinformation included in the report and a specific method of transmittingthe report through the transceiver 106 by the processor 102 may be basedon the afore-described embodiments.

Specifically, instructions and/or operations, which are controlled bythe processor(s) 202 of the second wireless device 200 and stored in thememory(s) 204, according to an embodiment of the present disclosure,will now be described.

While the following operations are described based on control operationsof the processor 202 from the perspective of the processor 202, softwarecode for performing these operations may be stored in the memory 204.The processor 202 may control the transceiver 206 to transmitinformation including a notification of using an SS/PBCH block and/or aCSI-RS as a PRS resource or for the purpose of determining a Tx/Rx beamto transmit/receive a PRS resource to the location server 90 of FIG. 33.

The processor 202 may configure a PRS resource. The processor 202 mayconfigure the PRS resource by receiving information related to the PRSresource configuration from the location server 90 of FIG. 33. Further,a specific method of configuring a PRS resource may be based on theafore-described embodiments. The processor 202 may control thetransceiver 206 to transmit at least one of a PRS, an SS/PBCH block, ora CSI-RS to the first wireless device 100. The processor 202 may controlthe transceiver 206 to receive a report related to the at least one ofthe PRS, the SS/PBCH block, or the CSI-RS from the first wireless device100. Specific information included in the report and a specific methodof transmitting the report by the first wireless device 100 may be basedon the afore-described embodiments.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described more specifically. One or more protocol layers may beimplemented by, without being limited to, one or more processors 102 and202. For example, the one or more processors 102 and 202 may implementone or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP,RRC, and SDAP). The one or more processors 102 and 202 may generate oneor more protocol data units (PDUs) and/or one or more service data units(SDUs) according to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document. Theone or more processors 102 and 202 may generate messages, controlinformation, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document. The one or more processors 102 and 202 maygenerate signals (e.g., baseband signals) including PDUs, SDUs,messages, control information, data, or information according to thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document and provide thegenerated signals to the one or more transceivers 106 and 206. The oneor more processors 102 and 202 may receive the signals (e.g., basebandsignals) from the one or more transceivers 106 and 206 and acquire thePDUs, SDUs, messages, control information, data, or informationaccording to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. As an example, one or moreapplication specific integrated circuits (ASICs), one or more digitalsignal processors (DSPs), one or more digital signal processing devices(DSPDs), one or more programmable logic devices (PLDs), or one or morefield programmable gate arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument may be implemented using firmware or software and the firmwareor software may be configured to include the modules, procedures, orfunctions. Firmware or software configured to perform the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be included in the one or more processors102 and 202 or stored in the one or more memories 104 and 204 so as tobe driven by the one or more processors 102 and 202. The descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be implemented using firmware or softwarein the form of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands.The one or more memories 104 and 204 may be configured by read-onlymemories (ROMs), random access memories (RAMs), electrically erasableprogrammable read-only memories (EPROMs), flash memories, hard drives,registers, cash memories, computer-readable storage media, and/orcombinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or radio signals/channels, mentioned in the methodsand/or operational flowcharts of this document, to one or more otherdevices. The one or more transceivers 106 and 206 may receive user data,control information, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, from one or moreother devices. For example, the one or more transceivers 106 and 206 maybe connected to the one or more processors 102 and 202 and transmit andreceive radio signals. For example, the one or more processors 102 and202 may perform control so that the one or more transceivers 106 and 206may transmit user data, control information, or radio signals to one ormore other devices. The one or more processors 102 and 202 may performcontrol so that the one or more transceivers 106 and 206 may receiveuser data, control information, or radio signals from one or more otherdevices. The one or more transceivers 106 and 206 may be connected tothe one or more antennas 108 and 208 and the one or more transceivers106 and 206 may be configured to transmit and receive user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, through the one ormore antennas 108 and 208. In this document, the one or more antennasmay be a plurality of physical antennas or a plurality of logicalantennas (e.g., antenna ports). The one or more transceivers 106 and 206may convert received radio signals/channels etc. from RF band signalsinto baseband signals in order to process received user data, controlinformation, radio signals/channels, etc. using the one or moreprocessors 102 and 202. The one or more transceivers 106 and 206 mayconvert the user data, control information, radio signals/channels, etc.processed using the one or more processors 102 and 202 from the baseband signals into the RF band signals. To this end, the one or moretransceivers 106 and 206 may include (analog) oscillators and/orfilters.

FIG. 30 illustrates another example of a wireless device applied to thepresent disclosure. The wireless device may be implemented in variousforms according to a use-case/service (refer to FIG. 28).

Referring to FIG. 30, wireless devices 100 and 200 may correspond to thewireless devices 100 and 200 of FIG. 29 and may be configured by variouselements, components, units/portions, and/or modules. For example, eachof the wireless devices 100 and 200 may include a communication unit110, a control unit 120, a memory unit 130, and additional components140. The communication unit may include a communication circuit 112 andtransceiver(s) 114. For example, the communication circuit 112 mayinclude the one or more processors 102 and 202 and/or the one or morememories 104 and 204 of FIG. 29. For example, the transceiver(s) 114 mayinclude the one or more transceivers 106 and 206 and/or the one or moreantennas 108 and 208 of FIG. 29. The control unit 120 is electricallyconnected to the communication unit 110, the memory 130, and theadditional components 140 and controls overall operation of the wirelessdevices. For example, the control unit 120 may control anelectric/mechanical operation of the wireless device based onprograms/code/commands/information stored in the memory unit 130. Thecontrol unit 120 may transmit the information stored in the memory unit130 to the exterior (e.g., other communication devices) via thecommunication unit 110 through a wireless/wired interface or store, inthe memory unit 130, information received through the wireless/wiredinterface from the exterior (e.g., other communication devices) via thecommunication unit 110. Accordingly, the detailed operating proceduresof the control unit 120 and the programs/code/commands/informationstored in the memory unit 130 may correspond to at least one operationof the processors 102 and 202 of FIG. 29 and at least one operation ofthe memories 104 and 204 of FIG. 29.

The additional components 140 may be variously configured according totypes of wireless devices. For example, the additional components 140may include at least one of a power unit/battery, input/output (I/O)unit, a driving unit, and a computing unit. The wireless device may beimplemented in the form of, without being limited to, the robot (100 aof FIG. 28), the vehicles (100 b-1 and 100 b-2 of FIG. 28), the XRdevice (100 c of FIG. 28), the hand-held device (100 d of FIG. 28), thehome appliance (100 e of FIG. 28), the IoT device (100 f of FIG. 28), adigital broadcast terminal, a hologram device, a public safety device,an MTC device, a medicine device, a fintech device (or a financedevice), a security device, a climate/environment device, the AIserver/device (400 of FIG. 28), the BSs (200 of FIG. 28), a networknode, etc. The wireless device may be used in a mobile or fixed placeaccording to a use-example/service.

In FIG. 30, the entirety of the various elements, components,units/portions, and/or modules in the wireless devices 100 and 200 maybe connected to each other through a wired interface or at least a partthereof may be wirelessly connected through the communication unit 110.For example, in each of the wireless devices 100 and 200, the controlunit 120 and the communication unit 110 may be connected by wire and thecontrol unit 120 and first units (e.g., 130 and 140) may be wirelesslyconnected through the communication unit 110. Each element, component,unit/portion, and/or module within the wireless devices 100 and 200 mayfurther include one or more elements. For example, the control unit 120may be configured by a set of one or more processors. As an example, thecontrol unit 120 may be configured by a set of a communication controlprocessor, an application processor, an Electronic Control Unit (ECU), agraphical processing unit, and a memory control processor. As anotherexample, the memory 130 may be configured by a Random Access Memory(RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM)), a flash memory,a volatile memory, a non-volatile memory, and/or a combination thereof.

An implementation example of FIG. 30 will be described in greater detailwith reference to the drawings.

FIG. 31 illustrates a hand-held device applied to the presentdisclosure. The hand-held device may include a smartphone, a smartpad, awearable device (e.g., a smartwatch or smartglasses), or a portablecomputer (e.g., a notebook). The hand-held device may be referred to asa mobile station (MS), a user terminal (UT), a mobile subscriber station(MSS), a subscriber station (SS), an advanced mobile station (AMS), or awireless terminal (WT).

Referring to FIG. 30, a hand-held device 100 may include an antenna unit108, a communication unit 110, a control unit 120, a memory unit 130, apower supply unit 140 a, an interface unit 140 b, and an input/output(I/O) unit 140 c. The antenna unit 108 may be configured as a part ofthe communication unit 110. Blocks 110 to 130/140 a to 140 c correspondto the blocks 110 to 130/140 of FIG. 28, respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from other wireless devices or BSs. Thecontrol unit 120 may perform various operations by controllingconstituent elements of the hand-held device 100. The control unit 120may include an application processor (AP). The memory unit 130 may storedata/parameters/programs/code/commands needed to drive the hand-helddevice 100. The memory unit 130 may also store input/outputdata/information. The power supply unit 140 a may supply power to thehand-held device 100 and include a wired/wireless charging circuit, abattery, etc. The interface unit 140 b may support connection of thehand-held device 100 to other external devices. The interface unit 140 bmay include various ports (e.g., an audio I/O port and a video I/O port)for connection to external devices. The I/O unit 140 c may input oroutput video information/signals, audio information/signals, data,and/or information input by a user. The I/O unit 140 c may include acamera, a microphone, a user input unit, a display unit 140 d, aspeaker, and/or a haptic module.

As an example, in the case of data communication, the I/O unit 140 c mayacquire information/signals (e.g., touch, text, voice, images, or video)input by a user and the acquired information/signals may be stored inthe memory unit 130. The communication unit 110 may covert theinformation/signals stored in the memory into radio signals and transmitthe converted radio signals to other wireless devices directly or to theBS. The communication unit 110 may receive radio signals from otherwireless devices or the BS and then restore the received radio signalsinto original information/signals. The restored information/signals maybe stored in the memory unit 130 and may be output as various types(e.g., text, voice, image, video, or haptic type) through the I/O unit140 c.

FIG. 32 illustrates a vehicle or an autonomous driving vehicle appliedto the present disclosure. The vehicle or autonomous driving vehicle maybe implemented by a mobile robot, a car, a train, a manned/unmannedAerial Vehicle (AV), a ship, etc.

Referring to FIG. 32, a vehicle or autonomous driving vehicle 100 mayinclude an antenna unit 108, a communication unit 110, a control unit120, a driving unit 140 a, a power supply unit 140 b, a sensor unit 140c, and an autonomous driving unit 140 d. The antenna unit 108 may beconfigured as a part of the communication unit 110. The blocks110/130/140 a to 140 d correspond to the blocks 110/130/140 of FIG. 28,respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as othervehicles, BSs (e.g., gNBs and road side units), and servers. The controlunit 120 may perform various operations by controlling elements of thevehicle or the autonomous driving vehicle 100. The control unit 120 mayinclude an Electronic Control Unit (ECU). The driving unit 140 a maycause the vehicle or the autonomous driving vehicle 100 to drive on aroad. The driving unit 140 a may include an engine, a motor, apowertrain, a wheel, a brake, a steering device, etc. The power supplyunit 140 b may supply power to the vehicle or the autonomous drivingvehicle 100 and include a wired/wireless charging circuit, a battery,etc. The sensor unit 140 c may acquire a vehicle state, ambientenvironment information, user information, etc. The sensor unit 140 cmay include an Inertial Measurement Unit (IMU) sensor, a collisionsensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor,a heading sensor, a position module, a vehicle forward/backward sensor,a battery sensor, a fuel sensor, a tire sensor, a steering sensor, atemperature sensor, a humidity sensor, an ultrasonic sensor, anillumination sensor, a pedal position sensor, etc. The autonomousdriving unit 140 d may implement technology for maintaining a lane onwhich a vehicle is driving, technology for automatically adjustingspeed, such as adaptive cruise control, technology for autonomouslydriving along a determined path, technology for driving by automaticallysetting a path if a destination is set, and the like.

For example, the communication unit 110 may receive map data, trafficinformation data, etc. from an external server. The autonomous drivingunit 140 d may generate an autonomous driving path and a driving planfrom the obtained data. The control unit 120 may control the drivingunit 140 a such that the vehicle or the autonomous driving vehicle 100may move along the autonomous driving path according to the driving plan(e.g., speed/direction control). In the middle of autonomous driving,the communication unit 110 may aperiodically/periodically acquire recenttraffic information data from the external server and acquiresurrounding traffic information data from neighboring vehicles. In themiddle of autonomous driving, the sensor unit 140 c may obtain a vehiclestate and/or surrounding environment information. The autonomous drivingunit 140 d may update the autonomous driving path and the driving planbased on the newly obtained data/information. The communication unit 110may transfer information about a vehicle position, the autonomousdriving path, and/or the driving plan to the external server. Theexternal server may predict traffic information data using AItechnology, etc., based on the information collected from vehicles orautonomous driving vehicles and provide the predicted trafficinformation data to the vehicles or the autonomous driving vehicles.

To perform the embodiments of the present disclosure, there may beprovided the location server 90 as illustrated in FIG. 33. The locationserver 90 may be logically or physically connected to a wireless device70 and/or a network node 80. The wireless device 70 may be the firstwireless device 100 of FIG. 29 and/or the wireless device 100 or 200 ofFIG. 28. The network node 80 may be the second wireless device 100 ofFIG. 29 and/or the wireless device 100 or 200 of FIG. 30.

The location server 90 may be, without being limited to, an AMF, an LMF,an E-SMLC, and/or an SLP and may be any device only if the device servesas the location server 90 for implementing the embodiments of thepresent disclosure. Although the location server 90 has used the name ofthe location server for convenience of description, the location server90 may be implemented not as a server type but as a chip type. Such achip type may be implemented to perform all functions of the locationserver 90 which will be described below.

Specifically, the location server 90 includes a transceiver 91 forcommunicating with one or more other wireless devices, network nodes,and/or other elements of a network. The transceiver 91 may include oneor more communication interfaces. The transceiver 91 communicates withone or more other wireless devices, network nodes, and/or other elementsof the network connected through the communication interfaces.

The location server 90 includes a processing chip 92. The processingchip 92 may include at least one processor, such as a processor 93, andat least one memory device, such as a memory 94.

The processing chip 92 may control one or more processes to implementthe methods described in this specification and/or embodiments forproblems to be solved by this specification and solutions for theproblems. In other words, the processing chip 92 may be configured toperform at least one of the embodiments described in this specification.That is, the processor 93 includes at least one processor for performingthe function of the location server 90 described in this specification.For example, one or more processors may control the one or moretransceivers 91 of FIG. 32 to transmit and receive information.

The processing chip 92 includes a memory 94 configured to store data,programmable software code, and/or other information for performing theembodiments described in this specification.

In other words, in the embodiments according to the presentspecification, when the memory 94 is executed by at least one processor,such as the processor 93, the memory 94 allows the processor 93 toperform some or all of the processes controlled by the processor 93 ofFIG. 32 or stores software code 95 including instructions for performingthe embodiments described in this specification.

Specifically, instructions and/or operations, which are controlled bythe processor 93 of the location server 90 and are stored in the memory94, according to an embodiment of the present disclosure will now bedescribed.

While the operations are described in the context of control operationsof the processor 93 from the perspective of the processor 93, softwarecode for performing these operations may be stored in the memory 94. Theprocessor 93 may control the transceiver 91 to receive informationincluding a notification of using an SS/PBCH block and/or a CSI-RS as aPRS resource or for the purpose of determining a Tx/Rx beam totransmit/receive a PRS resource from the second wireless device 200.

The processor 93 may control the transceiver 91 to transmit PRS resourceconfiguration information to the first wireless device 100 and/or thesecond wireless device 200 of FIGS. 23A and 23B. A specific method ofconfiguring a PRS resource may be based on the afore-describedembodiments. The processor 93 may control the transceiver 91 to receivea report related to at least one of a PRS, an SS/PBCH block, or a CSI-RSfrom the first wireless device 100 or the second wireless device 200.Specific information included in the report and a specific method oftransmitting the report by the first wireless device 100 or the secondwireless device 200 may be based on the afore-described embodiments.

FIG. 34 illustrates a signal process circuit for a transmission signal.

Referring to FIG. 34, a signal processing circuit 1000 may includescramblers 1010, modulators 1020, a layer mapper 1030, a precoder 1040,resource mappers 1050, and signal generators 1060. An operation/functionof FIG. 29 may be performed, without being limited to, the processors102 and 202 and/or the transceivers 106 and 206 of FIG. 29. Hardwareelements of FIG. 34 may be implemented by the processors 102 and 202and/or the transceivers 106 and 206 of FIG. 29. For example, blocks 1010to 1060 may be implemented by the processors 102 and 202 of FIG. 29.Alternatively, the blocks 1010 to 1050 may be implemented by theprocessors 102 and 202 of FIG. 29 and the block 1060 may be implementedby the transceivers 106 and 206 of FIG. 29.

Codewords may be converted into radio signals via the signal processingcircuit 1000 of FIG. 34. Herein, the codewords are encoded bit sequencesof information blocks. The information blocks may include transportblocks (e.g., a UL-SCH transport block, a DL-SCH transport block). Theradio signals may be transmitted through various physical channels(e.g., a PUSCH and a PDSCH).

Specifically, the codewords may be converted into scrambled bitsequences by the scramblers 1010. Scramble sequences used for scramblingmay be generated based on an initialization value, and theinitialization value may include ID information of a wireless device.The scrambled bit sequences may be modulated to modulation symbolsequences by the modulators 1020. A modulation scheme may includepi/2-Binary Phase Shift Keying (pi/2-BPSK), m-Phase Shift Keying(m-PSK), and m-Quadrature Amplitude Modulation (m-QAM). Complexmodulation symbol sequences may be mapped to one or more transportlayers by the layer mapper 1030. Modulation symbols of each transportlayer may be mapped (precoded) to corresponding antenna port(s) by theprecoder 1040. Outputs z of the precoder 1040 may be obtained bymultiplying outputs y of the layer mapper 1030 by an N*M precodingmatrix W. Herein, N is the number of antenna ports and M is the numberof transport layers. The precoder 1040 may perform precoding afterperforming transform precoding (e.g., DFT) for complex modulationsymbols. Alternatively, the precoder 1040 may perform precoding withoutperforming transform precoding.

The resource mappers 1050 may map modulation symbols of each antennaport to time-frequency resources. The time-frequency resources mayinclude a plurality of symbols (e.g., a CP-OFDMA symbols and DFT-s-OFDMAsymbols) in the time domain and a plurality of subcarriers in thefrequency domain. The signal generators 1060 may generate radio signalsfrom the mapped modulation symbols and the generated radio signals maybe transmitted to other devices through each antenna. For this purpose,the signal generators 1060 may include Inverse Fast Fourier Transform(IFFT) modules, Cyclic Prefix (CP) inserters, Digital-to-AnalogConverters (DACs), and frequency up-converters.

Signal processing procedures for a signal received in the wirelessdevice may be configured in a reverse manner of the signal processingprocedures 1010 to 1060 of FIG. 34. For example, the wireless devices(e.g., 100 and 200 of FIG. 30) may receive radio signals from theexterior through the antenna ports/transceivers. The received radiosignals may be converted into baseband signals through signal restorers.To this end, the signal restorers may include frequency downlinkconverters, Analog-to-Digital Converters (ADCs), CP remover, and FastFourier Transform (FFT) modules. Next, the baseband signals may berestored to codewords through a resource demapping procedure, apostcoding procedure, a demodulation processor, and a descramblingprocedure. The codewords may be restored to original information blocksthrough decoding. Therefore, a signal processing circuit (notillustrated) for a reception signal may include signal restorers,resource demappers, a postcoder, demodulators, descramblers, anddecoders.

The implementations described above are those in which the elements andfeatures of the present disclosure are combined in a predetermined form.Each component or feature shall be considered optional unless otherwiseexpressly stated. Each component or feature may be implemented in a formthat is not combined with other components or features. It is alsopossible to construct implementations of the present disclosure bycombining some of the elements and/or features. The order of theoperations described in the implementations of the present disclosuremay be changed. Some configurations or features of certainimplementations may be included in other implementations, or may bereplaced with corresponding configurations or features of otherimplementations. It is clear that the claims that are not expresslycited in the claims may be combined to form an implementation or beincluded in a new claim by an amendment after the application.

The specific operation described herein as being performed by the basestation may be performed by its upper node, in some cases. That is, itis apparent that various operations performed for communication with aterminal in a network including a plurality of network nodes including abase station can be performed by the base station or by a network nodeother than the base station. A base station may be replaced by termssuch as a fixed station, a Node B, an eNode B (eNB), an access point,and the like.

It will be apparent to those skilled in the art that the presentdisclosure may be embodied in other specific forms without departingfrom the spirit of the disclosure. Accordingly, the above descriptionshould not be construed in a limiting sense in all respects and shouldbe considered illustrative. The scope of the present disclosure shouldbe determined by rational interpretation of the appended claims, and allchanges within the scope of equivalents of the present disclosure areincluded in the scope of the present disclosure.

While the above-described method of acquiring positioning informationand the apparatus therefor have been described in the context of a 5GNewRAT system, the method and apparatus are also applicable to variousother wireless communication systems.

What is claimed is:
 1. A method performed by a user equipment (UE) in a wireless communication system, the method comprising: receiving configuration information comprising: (i) information regarding an identifier (ID) of a positioning reference signal (PRS) resource set, (ii) information regarding each ID of a plurality of PRS resources, (iii) information regarding a repetition number related to the plurality of PRS resources, and (iv) information regarding a PRS timing difference; and receiving a PRS based on the configuration information, wherein the plurality of PRS resources are included in one PRS resource set, wherein all of the plurality of PRS resources are repeated for a time duration of the one PRS resource set by the same repetition number identified according to the information regarding the repetition number, and wherein the PRS timing difference denotes a difference between (i) a timing related to a first PRS received from a first transmission point and (ii) a timing related to a second PRS received from a second transmission point.
 2. The method of claim 1, further comprising receiving information related to quasi-colocation (QCL) between at least one of the plurality of PRS resources and a reference signal, wherein the PRS is received further based on the information related to QCL and the reference signal.
 3. The method of claim 2, wherein the reference signal comprises at least one of another PRS or a synchronization/physical broadcast channel block (SS/PBCH), and wherein the QCL is QCL type D.
 4. The method of claim 2, further comprising: obtaining information related to an ID of a specific cell; and receiving the reference signal based on the ID of the specific cell.
 5. The method of claim 1, wherein a maximum number of PRS resources configurable for the UE is determined based on a capability of the UE.
 6. The method of claim 1, further comprising obtaining information related to an angle of a transmission beam for the PRS.
 7. The method of claim 1, wherein a resource element (RE) offset per at least one symbol the PRS resource mapped is configured in a frequency domain.
 8. The method of claim 7, further comprising obtaining information related to the at least one symbol.
 9. The method of claim 1, wherein the plurality of PRS resources are respectively related to a plurality of transmission beams different from each other.
 10. The method of claim 1, wherein the first transmission point is a reference transmission point.
 11. An apparatus configured to operate in a wireless communication system, the apparatus comprising: a transceiver; and at least one processor coupled with the transceiver, wherein the at least one processor is configured to: receive configuration information comprising: (i) information regarding an identifier (ID) of a positioning reference signal (PRS) resource set, (ii) information regarding each ID of a plurality of PRS resources, (iii) information regarding a repetition number related to the plurality of PRS resources, and (iv) information regarding a PRS timing difference; and receive a PRS based on the configuration information, wherein the plurality of PRS resources are included in one PRS resource set, wherein all of the plurality of PRS resources are repeated for a time duration of the one PRS resource set by the same repetition number identified according to the information regarding the repetition number, and wherein the PRS timing difference denotes a difference between (i) a timing related to a first PRS received from a first transmission point and (ii) a timing related to a second PRS received from a second transmission point.
 12. The apparatus of claim 11, wherein the at least one processor is further configured to receive information related to quasi-colocation (QCL) between at least one of the plurality of PRS resources and a reference signal, wherein the PRS is received further based on the information related to QCL and the reference signal.
 13. The apparatus of claim 12, wherein the reference signal comprises at least one of another PRS or a synchronization/physical broadcast channel block (SS/PBCH), and wherein the QCL is QCL type D.
 14. The apparatus of claim 11, wherein the apparatus is configured to communicate with at least one of: a mobile terminal, a network, or an autonomous driving vehicle other than a vehicle comprising the apparatus.
 15. An apparatus configured to operate in a wireless communication system, the apparatus comprising: at least one processor; and at least one memory storing at least one instruction causing the at least one processor to perform a method, wherein the method comprises: receive configuration information comprising: (i) information regarding an identifier (ID) of a positioning reference signal (PRS) resource set, (ii) information regarding each ID of a plurality of PRS resources, (iii) information regarding a repetition number related to the plurality of PRS resources, and (iv) information regarding a PRS timing difference; and receive a PRS based on the configuration information, wherein the plurality of PRS resources are included in one PRS resource set, wherein all of the plurality of PRS resources are repeated for a time duration of the one PRS resource set by the same repetition number identified according to the information regarding the repetition number, and wherein the PRS timing difference denotes a difference between (i) a timing related to a first PRS received from a first transmission point and (ii) a timing related to a second PRS received from a second transmission point.
 16. A method performed by a base station in a wireless communication system, the method comprising: transmitting configuration information comprising: (i) information regarding an identifier (ID) of a positioning reference signal (PRS) resource set, (ii) information regarding each ID of a plurality of PRS resources, (iii) information regarding a repetition number related to the plurality of PRS resources, and (iv) information regarding a PRS timing difference; and transmitting a PRS based on the configuration information, wherein the plurality of PRS resources are included in one PRS resource set, wherein all of the plurality of PRS resources are repeated for a time duration of the one PRS resource set by the same repetition number identified according to the information regarding the repetition number, and wherein the PRS timing difference denotes a difference between (i) a timing related to a first PRS transmitted by a first transmission point and (ii) a timing related to a second PRS transmitted by a second transmission point. 